Astrology glossary

A

Ascendant

The sign and degree rising on the eastern horizon at the moment you were born. It marks the start of the first house and sets the order of the other houses. It is associated with the attitude you first project into the world and the first impression you make. Because it changes roughly every two hours, it is very sensitive to birth time.

Aspect

The distance between two planets or chart points, expressed in degrees. Conjunction (0°), sextile (60°), square (90°), trine (120°) and opposition (180°) are the most commonly used aspects. An aspect does not have to be exact to count; it is enough for it to fall within a certain allowance, called the orb.

Ayanamsa

The difference in degrees between the tropical and sidereal zodiacs. Because the equinoxes shift, this difference grows very slowly over the years and is now about 24 degrees. In Vedic astrology it is used to convert planetary positions from tropical to sidereal values. Different schools adopt slightly different ayanamsa values.

B

Birth chart

A diagram showing the positions of the planets in the signs and houses at the moment a person was born, along with the aspects they form with one another. It is also known as the natal chart. It is calculated from the date, time and place of birth; all three must be accurate for the planetary positions and the Ascendant to be read fully.

Birth time rectification

A method of estimating an unknown or uncertain birth time by working backward from the events of a person's life. The astrologer tries to correct the time by comparing the dates of important events with transits and progressions. The result is an estimate, not a certainty.

C

Chiron

A small celestial body discovered in 1977 that orbits between Saturn and Uranus. In astrology it is known as the "wounded healer" and represents deep wounds and the healing potential that grows out of them. It travels around the zodiac in about 50 years.

Combust planet

In traditional astrology, the name given to a planet within about eight and a half degrees of the Sun. The planet's function is thought to be overshadowed by the Sun's light. A position very close to the Sun, within about half a degree, is by contrast considered especially strong.

Composite chart

A third chart created from the midpoints of the planets in two people's birth charts. It describes the relationship's own dynamics and purpose. While synastry compares two charts, the composite chart reads the relationship as a single entity.

Conjunction

The aspect formed when two planets are at around the same degree (0 degrees). It combines and intensifies the energies of both planets. The tone of a conjunction depends on whether the planets coming together are compatible with each other.

D

Dasha

A timing system in Vedic astrology that divides life into planetary periods. The most common is the Vimshottari dasha; it begins according to the Moon's nakshatra at birth and consists of periods ruled in turn by nine planets over a total cycle of 120 years. Each period brings the themes of its planet to the fore.

Decan

Each of the three 10-degree subdivisions of a sign. Each decan is assigned its own sub-ruler, which helps refine the interpretation of the sign. People born in the first, second and third decans of the same sign can carry different tones.

Descendant

The point on the western horizon directly opposite the Ascendant, marking the start of the seventh house. It is associated with the qualities we meet in relationships and partnerships and feel are missing in ourselves.

Detriment

A planet's placement in the sign opposite the one it rules. For example, Venus is in detriment in Aries and Scorpio. Here the planet is cut off from its natural expression and carries out its function with more difficulty.

E

Eclipse

The shadowing of the Sun or the Moon. A solar eclipse occurs at a new moon and a lunar eclipse at a full moon, and both happen near the lunar nodes. In astrology eclipses are associated with powerful themes of beginnings and endings.

Ecliptic

The apparent path the Sun traces across the sky over a year, as seen from Earth. The signs are arranged along this line, and the planets' orbits also lie very close to it. The zodiac is a narrow band around the ecliptic.

Electional astrology

The branch of astrology that tries to choose a suitable time to begin something. A starting moment is selected by looking at planetary positions, the condition of the Moon and the aspects. This approach has no scientific basis; it should be regarded as a traditional method of interpretation.

Element

The division of the signs into four groups: fire, earth, air and water. Fire describes action and passion, earth the tangible, air thought and communication, and water emotion and intuition. Each element contains three signs.

Ephemeris

A table or data set listing the positions of the planets on specific dates. It forms the basis of astrological calculations. Today it is produced through astronomical calculations and gives positions to the degree and minute.

Equinox

The two moments when the Sun crosses the celestial equator and night and day are nearly equal: the spring and autumn equinoxes. In the tropical zodiac, the spring equinox is taken as 0 degrees Aries. The equinoxes shift slowly; this phenomenon is called precession.

Essential dignities

In traditional astrology, the system that determines how strong or weak a planet is considered to be in the sign it occupies. Rulership, exaltation, detriment and fall are its main levels; there are also finer criteria such as triplicity, terms and decans. It is used to describe whether a planet feels "at home" or like a "stranger" in its sign.

Exaltation

In traditional astrology, a planet's placement in a sign where it works especially strongly and harmoniously. For example, the Sun is considered exalted in Aries and the Moon in Taurus. Unlike a planet in the sign it rules, it is associated with the theme of being hosted like an "honored guest."

F

Fall

In traditional astrology, a planet's placement in the sign opposite the sign of its exaltation. Here the planet does not feel at ease and struggles to carry out its function. For example, the Sun's sign of fall is Libra. This should be read not as a "bad" placement but as one that requires effort.

Fixed stars

Stars whose positions in the sky appear almost fixed compared with the planets; Regulus, Algol and Spica are among them. Especially in traditional interpretation, a fixed star conjunct a planet is considered to carry meaning as well.

Full moon

The phase in which the Moon is directly opposite the Sun and its face appears fully lit. In astrology it is interpreted as a time of culmination, awareness and release. When it occurs near the lunar nodes, a lunar eclipse can take place.

G

Generational planets

Uranus, Neptune and Pluto. Because they move very slowly, they occupy similar signs in the charts of everyone born in the same period. For this reason they are associated with generational themes as much as individual ones. Jupiter and Saturn are the social planets that bridge these and the personal planets.

Grand trine

A pattern in which three planets in signs of the same element form an equilateral triangle, about 120 degrees apart. It brings flow, natural talent and ease. Too much ease can reduce the drive to take action.

H

Hellenistic astrology

The astrological tradition that developed in the Mediterranean world from roughly the first century BCE to the seventh century CE. The seven planets, whole sign houses, essential dignities and timing techniques are at its core. It is considered the root of Western astrology and has seen a revival of interest in recent years.

Horary astrology

A traditional branch that seeks an answer to a specific question using a chart cast for the moment the question is asked. The chart is drawn up for the time of the question, not the time of birth. Because it claims to give definite answers, it is a method to approach with caution.

House

Each of the twelve sections of the birth chart wheel. Each house represents an area of life: identity, money, communication, family, creativity, health, relationships, shared resources, beliefs, career, community and the subconscious. The house a planet occupies shows in which area of life its influence will be felt.

House ruler

The planet that rules the sign on the cusp of a house. For example, if Libra is on the seventh house cusp, the ruler of the seventh house is Venus. By looking at where the ruler sits in the chart, astrologers interpret where the matters of that house flow in life.

House system

The calculation method that sets the boundaries of the twelve houses in a birth chart. Placidus, Koch, equal houses and whole sign houses are the most common. Depending on the system used, the same chart may place some planets in different houses.

I

IC (Imum Coeli)

The lowest point of the chart, usually the cusp of the fourth house. It lies directly opposite the MC. It is associated with roots, family, home and the inner world.

L

Lagna

The name for the rising sign in Vedic astrology. It is considered the center of the chart and the starting point of the houses. It is usually used together with the whole sign house system.

Lilith

A calculated point, also known as Black Moon Lilith, representing the point in the Moon's orbit farthest from Earth. In astrology it is associated with themes of suppressed anger, independence and conflict with social norms. It should not be confused with the asteroid and the mythological figure of the same name.

Luminaries

The name given in astrology to the Sun and the Moon. Astronomically, neither is a planet; in the chart, however, they are interpreted like planets. The Sun represents consciousness and identity, the Moon emotions and needs.

Lunar nodes

The two points where the Moon's orbit crosses the ecliptic: the North Node and the South Node. They lie exactly opposite each other and form the axis along which eclipses occur. In astrology they are associated with the direction of growth and with habitual patterns of behavior. The nodes travel backward through the zodiac, completing a full circuit in about 18.6 years.

Lunar return

The moment the Moon returns to its position in your birth chart, which happens roughly every 27.3 days. The chart cast for this moment is used to interpret the emotional themes of the month ahead. It is like a much shorter-term counterpart of the solar return.

M

MC (Medium Coeli)

Also known as the Midheaven, the highest point of the chart, usually the cusp of the tenth house. It is associated with career, public reputation and life purpose. It lies directly opposite the IC.

Mercury retrograde

The period when Mercury, as seen from Earth, appears to move backward across the sky. It happens three or four times a year and lasts about three weeks. In astrology it is interpreted as a time to review and slow down in matters of communication, travel and technology.

Modality

The division of the signs into three groups: cardinal, fixed and mutable. Cardinal signs (Aries, Cancer, Libra, Capricorn) initiate; fixed signs (Taurus, Leo, Scorpio, Aquarius) sustain; mutable signs (Gemini, Virgo, Sagittarius, Pisces) adapt and transform. It is also called the mode.

Moon phases

The changing appearances of the Moon, depending on its position relative to the Sun. The new moon, first quarter, full moon and last quarter are the main phases; one cycle lasts about 29.5 days. In astrology each phase is associated with a different rhythm: beginning, taking action, reaching a peak and letting go.

Moon sign

The sign the Moon was in at the moment of birth. It describes emotional needs, habits and the way you find a sense of security. Because the Moon spends about two and a half days in each sign, finding your Moon sign sometimes requires your birth time as well.

Mundane astrology

The branch of astrology that studies countries, societies, the economy and world events rather than individuals. It draws on the cycles of the slow-moving planets and on the founding charts of nations. Its predictions have not been scientifically verified.

N

Nakshatra

The lunar mansions of Vedic astrology, obtained by dividing the zodiac into 27 equal parts; each spans 13 degrees 20 minutes. Each nakshatra is associated with a symbol, a deity and a particular character. The Moon's nakshatra at birth is especially important in Vedic interpretation.

Navamsa

A divisional chart in Vedic astrology, also called the D9, obtained by dividing each sign into nine equal parts. It accompanies the main chart. It is used to examine marriage, compatibility and spiritual potential.

New moon

The phase in which the Moon and the Sun are conjunct in the same sign and the Moon is not visible. In astrology it is interpreted as a time for new beginnings and setting intentions. When it occurs near the lunar nodes, a solar eclipse can take place.

O

Opposition

The aspect formed when two planets sit at opposite ends of the zodiac, about 180 degrees apart. It is associated with themes of seeking balance, polarization and mirroring in relationships. The full moon is an opposition between the Sun and the Moon.

Orb

The allowance that determines how far an aspect may deviate from its exact degree. For example, if an eight-degree orb is used for the square, any distance between 82 and 98 degrees counts as a square. The tighter the orb, the more pronounced the aspect is considered to be.

P

Part of Fortune

A mathematical point calculated from the positions of the Ascendant, the Sun and the Moon; it is also known as the Lot of Fortune. In traditional astrology it is believed to show where physical and material ease and prosperity can be found.

Personal planets

The Sun, Moon, Mercury, Venus and Mars. Because they move quickly, they are considered to shape a person's everyday character, emotions and ways of thinking and loving. The individual tone of a chart is read from these planets.

Placidus

One of the most widely used house systems, based on time. It sets the house boundaries according to how long it takes a sign to rise from the horizon to the Midheaven. The houses are not equal in size, and they cannot be calculated at very high latitudes such as the polar regions.

Planet

In astrology, the name given to the celestial bodies interpreted in the chart, each representing a function of life. The Sun and Moon are included in this definition even though they are not planets astronomically. Mercury represents thinking, Venus loving, Mars taking action and Saturn responsibility.

Precession

The backward drift of the equinox points through the zodiac, caused by the slow wobble of Earth's axis. A full cycle takes about 26,000 years. This is the source of the difference between the tropical and sidereal zodiacs, that is, the ayanamsa.

Progression

A forecasting technique in which each day after birth represents one year of life. Its most common form is the secondary progression: the sky on the 30th day after birth represents the inner world at age 30. It is used to track inner development and slow changes.

Q

Quarter moon

The two phases in which the Moon forms a 90-degree angle with the Sun: the first quarter and the last quarter. In these phases half of the Moon appears lit. In astrology the first quarter is interpreted as a time of action and testing, and the last quarter as a time of evaluation and gathering oneself.

Quincunx

The 150-degree aspect between two planets, also known as the inconjunct. It forms between signs that share neither an element nor a modality. It is associated with the theme of needing to adapt and adjust.

R

Rahu and Ketu

The names given in Vedic astrology to the Moon's north and south nodes. Rahu represents desire and worldly ambition, Ketu letting go and spiritual seeking. They stand exactly opposite each other and are known as the shadow planets.

Rashi

The Vedic astrology term for a sign. It is determined according to the sidereal zodiac. The rashi the Moon occupies is considered a person's main sign.

Retrograde

When a planet, as seen from Earth, appears to move backward through the zodiac. In reality the planet does not move backward; the relative speeds of Earth and the planet create this appearance. The Sun and Moon are never retrograde.

Ruling planet

The planet traditionally considered responsible for a sign. For example, the ruler of Aries is Mars and the ruler of Taurus is Venus. In modern astrology, Pluto is also considered the ruler of Scorpio, Uranus of Aquarius and Neptune of Pisces.

S

Saturn return

The period when Saturn returns to its position in your birth chart. It happens roughly every 29.5 years, and the first return occurs between the ages of 27 and 30. It is associated with themes of maturing, responsibility and reviewing the structure of one's life.

Sextile

The 60-degree aspect between two planets. It brings opportunity and harmonious cooperation. It is not as free-flowing as the trine; making the most of the opportunity takes some effort.

Shadow period

The time before a planet turns retrograde and after its retrograde ends, during which it travels through the range of degrees it covers while retrograde. It is discussed most often for Mercury. During these periods the themes of the retrograde begin to appear in advance and settle in afterward.

Sidereal zodiac

A zodiac system that defines the signs according to the fixed stars. It is used in Vedic astrology. It differs from the tropical zodiac by the ayanamsa, that is, about 24 degrees.

Sign

Each of the twelve equal 30-degree sections of the ecliptic. Every sign is defined by an element, a modality and a ruling planet. The Sun's passage through these sections in turn over the course of a year forms the basis of the zodiac sign system.

Solar return

The moment each year, around your birthday, when the Sun returns to its position in your birth chart. The chart cast for this moment is used to interpret the themes of the year ahead. The solar return chart can also be read by placing it over the birth chart.

Square

The aspect formed when two planets are about 90 degrees apart. It brings tension, friction and a pressure that spurs action. Although it is considered challenging, it is often the aspect that helps a person grow.

Stellium

A gathering of three or more planets in the same sign or house. The theme of that sign or house becomes dominant in the person's chart. Along with concentration, it can also create problems of balance.

Sun sign

The sign the Sun was in at the moment you were born. It describes identity, life force and the direction of growth. It is the best-known placement in horoscope readings, but it is only one part of the chart.

Synastry

The comparison of two people's birth charts by overlaying one on the other. It looks at the cross-aspects between the planets and at where one person's planets fall in the other's houses. It is used to understand the areas of harmony and friction in a relationship.

T

T-square

An aspect pattern in which two planets are in opposition and both square a third planet. It brings tension and an intense pressure to act. The third planet is considered the release point for this tension.

Traditional planets

The seven celestial bodies visible to the naked eye: the Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn. Before Uranus, Neptune and Pluto were discovered, these were the only ones used in astrology. They still play a central role in Hellenistic and Vedic astrology.

Transit

The aspects that the planets currently moving through the sky make to the points in your birth chart. Transits are used to interpret timing and daily influences. Transits of slow planets describe long-lasting periods, while transits of fast planets describe short-lived themes.

Trine

The aspect formed when two planets are about 120 degrees apart, occurring between signs of the same element. It brings flow, ease and natural talent. Because it is such a comfortable aspect, it can sometimes be left undeveloped.

Tropical zodiac

A zodiac system that defines the signs according to the seasons, that is, the spring equinox. Western astrology uses this system. Aries begins at the spring equinox.

V

Vertex

The point where the ecliptic intersects the prime vertical in its western half, usually found between the fifth and eighth houses. In astrology it is associated with encounters that feel fated. Its interpretation is debated among astrologers.

Void-of-course Moon

The period after the Moon completes its last major aspect with another planet before leaving its current sign, lasting until it enters the next sign. It can last anywhere from a few minutes to a day. Some astrologers advise against starting new ventures during this window; this is a traditional approach and not everyone agrees with it.

W

Whole sign houses

A house system in which the entire sign containing the Ascendant counts as the first house, and the following signs become the second, third and subsequent houses in order. Each house is exactly 30 degrees. It is widely used in Hellenistic and Vedic astrology.

Y

Yod

An aspect pattern in which two planets form a sextile and both form a quincunx with a third planet. It is also known as the "Finger of God." It is associated with a call to make adjustments and find a new direction.

Z

Zodiac

The 360-degree band that runs along the ecliptic and is divided into twelve equal signs. The Sun, Moon and planets move within this band. There are two main systems: tropical and sidereal.