Astrology Glossary — Complete A-Z Reference
A reference for the terms that recur in astrological reading. Use the birth chart reading guide for a step-by-step walkthrough, and the free birth chart calculator to cast a chart you can apply these terms to.
Anaretic degree
The 29th degree of any sign — the final degree before the cusp. Planets in the anaretic degree are said to be in a state of urgency or completion, as if pressed up against a deadline.
Angular house
The 1st, 4th, 7th, and 10th houses — those beginning at the chart's four cardinal angles (ascendant, IC, descendant, MC). Planets in angular houses are read as prominent and active.
Applying aspect
An aspect that is becoming more exact — the faster planet is moving toward the slower. Applying aspects are read as stronger and more event-like than separating ones.
Ascendant
The zodiac sign and degree rising on the eastern horizon at birth, marking the cusp of the first house. Also called the rising sign or Lagna in Vedic astrology. The ascendant anchors the entire chart.
Aspect
An angular relationship between two planets measured along the ecliptic. The five major (Ptolemaic) aspects are conjunction (0°), sextile (60°), square (90°), trine (120°), and opposition (180°).
Ayanamsa
The angular offset between the tropical and sidereal zodiacs, used to convert tropical positions into sidereal. The Lahiri ayanamsa is the Indian government standard, currently about 24°10′.
Benefic
A planet traditionally considered favourable. Jupiter is the greater benefic, Venus the lesser benefic. Mercury and the Moon are conditionally benefic depending on placement.
Bowl chart
A chart shape where all planets fall within one half of the wheel. The empty half is read as what the person instinctively reaches toward.
Cadent house
The 3rd, 6th, 9th, and 12th houses — those just past the angular houses in the order of diurnal motion. Planets in cadent houses are read as quieter or more transitional.
Cardinal sign
Aries, Cancer, Libra, Capricorn — the signs at the start of each season. Cardinal energy initiates.
Chart ruler
The planet that rules the rising sign. Its sign, house, and aspects flavour the entire chart.
Chiron
An object discovered in 1977 orbiting between Saturn and Uranus, classed as a centaur. Astrologically Chiron represents the wound that becomes wisdom — the place where the gift and the injury are the same.
Composite chart
A chart constructed from the midpoints of two natal charts, read as the chart of the relationship itself.
Conjunction
An aspect of 0° — two planets in the same place. The two energies fuse.
Cusp
The boundary between two adjacent houses or signs. Planets near a cusp are read as participating in both adjacent zones.
Dasha
A timed planetary period in Vedic astrology. The most common system, Vimshottari, runs 120 years and is calculated from the natal Moon's nakshatra.
Decan
A 10° subdivision of a zodiac sign. Each sign has three decans, traditionally given sub-rulerships.
Descendant
The cusp of the seventh house, opposite the ascendant. Describes the qualities one looks for in partnership.
Dignified
A planet placed in a sign where it is naturally strong — its own sign (rulership) or its sign of exaltation.
Dispositor
The planet that rules the sign in which another planet is placed. The Sun in Cancer is disposed by the Moon.
Dominant planet
The planet most strongly emphasised in a chart by sign placement, house placement, aspects, and angularity. Often the chart's defining signature.
Eclipse
A new or full Moon occurring near the lunar nodes. Eclipses are read as transit-amplifiers — what they activate is more lasting than ordinary lunations.
Element
Fire, earth, air, or water. Each zodiac sign belongs to one element. The balance of elements in a chart is a primary diagnostic.
Exalted
A planet placed in the sign where it is most honoured. The Sun is exalted in Aries, the Moon in Taurus, Jupiter in Cancer, and so on.
Fall
A planet placed in the sign opposite its exaltation, considered a position of weakness. The Sun is in fall in Libra, the Moon in Scorpio.
Fixed sign
Taurus, Leo, Scorpio, Aquarius — the signs at the heart of each season. Fixed energy stabilises and resists change.
Grand Cross
Four planets forming two oppositions and four squares — a square pattern across the chart. A configuration of intense and ongoing internal pressure.
Grand Trine
Three planets each 120° apart, forming an equilateral triangle in one element. A configuration of natural ease in that element.
House system
A method of dividing the celestial sphere into twelve sectors. Major systems include Placidus (most common in modern Western), Whole Sign (Hellenistic and Vedic standard), Koch, Equal, and Porphyry.
Imum Coeli (IC)
The lowest point of the chart, opposite the midheaven. The cusp of the fourth house. Describes roots, family of origin, and the foundation of the self.
Intercepted sign
A zodiac sign that is fully contained within a house, with no cusp on it. Planets in intercepted signs are read as having a delayed or constrained expression.
Julian Day
A continuous count of days since 1 January 4713 BCE. Used as the standard input to astronomical calculations.
Koch houses
A house system devised by Walter Koch (1971), based on the diurnal arc traversed by the ascending degree. Popular in Germany and central Europe.
Lagna
Sanskrit for ascendant. The most important point in a Vedic chart.
Luminaries
The Sun and Moon. The two lights of the chart.
Midheaven (MC)
The point on the ecliptic culminating at birth — the highest point of the chart, the cusp of the tenth house. Describes vocation and public reputation.
Modality
Cardinal, fixed, or mutable — the three modes of action expressed by the zodiac signs.
Mutable sign
Gemini, Virgo, Sagittarius, Pisces — the signs at the end of each season. Mutable energy adapts and prepares for change.
Nakshatra
A 13°20′ lunar mansion in Vedic astrology. There are twenty-seven, each with a presiding deity, ruling planet, and characteristic qualities.
Natal chart
The chart of the moment and place of birth. Synonymous with birth chart.
Night chart
A chart in which the Sun is below the horizon at the time of birth. Affects traditional sect-based interpretations of benefic and malefic strength.
Nodes
The two points where the Moon's orbit crosses the ecliptic. The North Node (Rahu in Vedic) is read as the karmic direction; the South Node (Ketu) as inherited gifts and what is being released.
Orb
The allowable distance from an exact aspect. Standard orbs range from 8° (conjunctions involving the luminaries) down to 1-2° (minor aspects).
Out of bounds
A planet's declination exceeding 23°27′ (the Sun's maximum). Out-of-bounds planets behave less predictably and often signal exceptional or eccentric expression.
Part of Fortune
An Arabic part calculated from the positions of the Sun, Moon, and ascendant. Read as a point of natural good fortune and flow.
Peregrine
A planet in no dignity at all — neither in its own sign, exaltation, fall, or detriment. Peregrine planets are read as wandering or unrooted.
Placidus
The most common house system in modern Western astrology, devised by Placidus de Titis in the 17th century. Based on the time taken for a degree of the ecliptic to rise from the IC to the ascendant.
Progressed chart
A chart aged symbolically. The most common method, secondary progression, advances the chart one day for each year of life.
Retrograde
Apparent backward motion of a planet against the zodiac, caused by Earth overtaking it (or being overtaken). Retrograde planets are read as turning their function inward.
Rising sign
Synonym for ascendant.
Rulership
The relationship between a planet and the sign(s) it governs. Mars rules Aries; Venus rules Taurus and Libra; Mercury rules Gemini and Virgo; the Moon rules Cancer; the Sun rules Leo; Pluto and Mars rule Scorpio; Jupiter rules Sagittarius and Pisces; Saturn rules Capricorn and Aquarius (with Uranus as Aquarius co-ruler and Neptune as Pisces co-ruler in the modern system).
Separating aspect
An aspect that is becoming less exact — the faster planet is moving away from the slower. Separating aspects are read as receding influences.
Sidereal
The zodiac fixed to the actual constellations. Used in Vedic astrology and by some Western siderealists.
Stellium
Three or more planets in the same sign or house. A concentration of the chart's energy in one zone.
Succedent house
The 2nd, 5th, 8th, and 11th houses — those just after the angular houses. Read as resource-building zones.
Synastry
The astrological comparison of two charts, used for relationship analysis.
T-square
Two planets in opposition both squared by a third. The apex planet (the one squared by both) carries the tension and is often the chart's defining lever.
Transit
The position of a planet today (or any chosen date) relative to the natal chart. Transits describe how the natal pattern is being activated by the moving sky.
Tropical zodiac
The zodiac fixed to the seasons — 0° Aries always equals the Northern spring equinox. The standard in Western astrology.
Void of course
A Moon that will form no more major aspects before changing signs. A transit phenomenon used in electional astrology.
Whole sign houses
The oldest house system, in which the rising sign is the entire first house, the next sign the entire second, and so on. Standard in Hellenistic and Vedic astrology.
Yod
Two planets in sextile both inconjunct (150°) a third. A so-called "finger of God" pattern that focuses on the apex planet and is read as fated and adjusting.
Antiscion
A point of equal distance from the Cancer-Capricorn axis (the solstitial axis). A planet's antiscion is its mirror image across that axis. Traditionally read as a hidden conjunction — a connection that operates beneath the surface of the chart.
Astrological age
A roughly 2,160-year period during which the spring equinox sun rises against the backdrop of a particular constellation. We are currently leaving the Age of Pisces and entering the Age of Aquarius.
Cazimi
A planet within 17 arcminutes of the exact degree of the Sun. Cazimi planets are traditionally considered enormously strengthened — "in the heart of the Sun" — rather than burned by combustion.
Chart rectification
The process of working backwards from major life events to determine an unknown or uncertain birth time. A skilled astrologer can typically rectify a chart to within a few minutes given enough datable events.
Composite chart
A chart constructed from the planet-by-planet midpoints of two natal charts. Read as the chart of the relationship itself, distinct from synastry between the two individual charts.
Contraparallel
Two planets at equal but opposite declinations — one north of the celestial equator and one south by the same amount. Read as similar in meaning to an opposition.
Culmination
The moment a planet crosses the meridian. The midheaven is the point of the ecliptic culminating at birth.
Decile
A minor aspect of 36° (one tenth of the zodiac). Read as a mild flow of talent between the two planets involved.
Declination
A planet's distance north or south of the celestial equator, measured in degrees. Distinct from ecliptic latitude. Used in parallel and contraparallel aspects and in determining out-of-bounds status.
Doryphory
A traditional configuration in which planets surround a luminary as bodyguards, traditionally rising before the Sun or setting after the Moon. Said to amplify the dignity of the luminary.
Duad
A 2.5° subdivision of a zodiac sign — twelve duads per sign. Each duad is given a sub-sign rulership beginning with the sign itself.
Electional astrology
The branch of astrology concerned with choosing an auspicious moment for an undertaking — a wedding, a launch, surgery. Reverses natal astrology: instead of reading a chart, you select a chart.
Firdaria
A medieval Persian system of timed planetary periods, in which each planet rules a fixed number of years in life. Distinct from Vimshottari dasha.
Hayz
A traditional dignity in which a planet is in its preferred sect (diurnal or nocturnal), in a sign matching its gender, and on the appropriate side of the horizon. A planet in hayz is at full traditional strength.
Heliacal rising
A star or planet's first visible rising before sunrise after a period of being hidden by the Sun's light. Heliacal risings were the foundation of ancient predictive astrology.
Horary astrology
The branch of astrology that answers a specific question by casting a chart for the moment the question was asked. A distinct technique with its own rules of judgment.
Hyleg
The traditional "life-giver" of a chart — usually the Sun, Moon, or ascendant — used in classical predictive techniques to estimate length of life.
Lot of Fortune
An Arabic part calculated from the longitudes of the Sun, Moon, and ascendant. The formula reverses for day vs night charts. Read as a point of natural good fortune and embodied flourishing.
Mundane astrology
The branch of astrology concerned with nations, weather, economies, and world events rather than individuals.
Mutual reception
Two planets each placed in the sign ruled by the other — Mars in Venus's sign and Venus in Mars's sign, for example. Read as a strong, supportive link between the two planets, regardless of aspect.
Parallels
Two planets at the same declination, both north or both south of the celestial equator. Read as similar in meaning to a conjunction.
Partile aspect
An aspect that is exact to within 1°. Partile aspects are read as far stronger than wider aspects of the same kind.
Platic aspect
An aspect within orb but not exact. The opposite of partile.
Prenatal eclipse
The most recent solar or lunar eclipse before a person's birth. Sometimes used as a sensitive degree for life themes.
Primary directions
An ancient predictive technique that ages the chart by rotating it forward at the rate of the diurnal motion of the celestial sphere — roughly one degree per year of life.
Profections
An ancient predictive technique that advances the ascendant one whole sign each year of life. The sign reached for the year becomes the profected ascendant; its ruler becomes the time-lord of the year.
Sect
The classification of a chart as diurnal (Sun above the horizon at birth) or nocturnal (Sun below). Sect is fundamental to traditional astrology and modifies how planets are read as benefic or malefic.
Solar arc directions
A predictive technique in which every planet is advanced by the same amount the Sun has moved by secondary progression. A simple, robust method of timing major life themes.
Stationary planet
A planet apparently stopped in the sky as it shifts between direct and retrograde motion. Stationary planets are read as exceptionally strong and prominent in the chart.
Syzygy
The most recent New or Full Moon before a person's birth. Used in traditional astrology as a sensitive degree.
Triplicity
A traditional dignity in which a planet is in its element (fire, earth, air, or water). Each element has three triplicity rulers — diurnal, nocturnal, and participating — used in classical reading.