Astrology glossary
The terms our reports use, defined in plain language and grounded in the same classical sources the calculations follow. Each entry links to the article that goes deeper, and to the tool where you can see the term in your own chart.
Reading a chart
- SectSect is the division of a chart into day or night, decided by whether the Sun is above or below the horizon, and it changes which planets are favoured.
- CombustA planet is combust when it sits within about eight degrees of the Sun, close enough that classical astrology treats it as overwhelmed by the Sun's light.
- CazimiCazimi is a planet within about seventeen minutes of arc of the Sun's exact degree, which classical astrology reads as the strongest place a planet can be.
- Under the beamsA planet is under the beams when it is roughly eight to seventeen degrees from the Sun, too close to be easily visible but not close enough to be called combust.
- DecanA decan is a ten-degree third of a zodiac sign, giving thirty six in all, each with a sub-ruler that tints the meaning of the sign.
- AscendantThe Ascendant, or rising sign, is the zodiac degree climbing over the eastern horizon at the moment of birth, and it begins the first house.
- MidheavenThe Midheaven, or Medium Coeli, is the highest point the ecliptic reaches at the moment of birth, and it marks the direction of career, reputation and public standing.
- AspectAn aspect is a specific angle between two planets, and the five classical ones are the conjunction, sextile, square, trine and opposition.
- OrbAn orb is the tolerance around an exact aspect, the number of degrees within which two planets still count as connected.
- StelliumA stellium is a cluster of three or more planets in one sign or one house, which concentrates a chart's weight in a single area.
- Lunar nodesThe lunar nodes are the two points where the Moon's orbit crosses the ecliptic, always opposite each other, and eclipses happen when a lunation falls near them.
- House systemA house system is a method for dividing the chart into twelve houses, and the common ones disagree because they divide different things: space, time or the ecliptic itself.
- ElementThe four elements, fire, earth, air and water, group the twelve signs into four triplicities and describe the basic quality each sign works through.
- ConjunctionA conjunction is two bodies at the same degree of the zodiac, the aspect of fusion, in which each planet takes on the other's business rather than merely commenting on it.
- OppositionAn opposition is two bodies 180 degrees apart, facing each other across the chart, the aspect of confrontation and of awareness that arrives through another person or another side.
- TrineA trine is two bodies 120 degrees apart, in signs of the same element, and it is the easiest of the five major aspects: the two planets agree without effort.
- SquareA square is two bodies 90 degrees apart, in signs of the same modality but incompatible elements, and it is the aspect of friction: two planets that want the same kind of action for different reasons.
- SextileA sextile is two bodies 60 degrees apart, in compatible elements, and it is the aspect of opportunity: a cooperation that is available but has to be taken up.
- Applying and separatingAn aspect is applying when the faster planet is still moving toward exactness and separating once it has passed, and traditional astrology treats the applying half as the one that carries weight.
- CuspA cusp is the boundary line of a house, the degree at which one of the twelve divisions begins, and by extension the point where a sign gives way to the next.
- Birth chartA birth chart is a map of the sky as it stood from your birthplace at the moment you were born, showing the planets by sign and house and the aspects between them.
- Whole sign housesWhole sign houses make each house exactly one sign, with the sign holding the Ascendant becoming the entire first house, which is the oldest and simplest of the house systems.
- PlacidusPlacidus is a time-based house system that divides the hours it takes a degree to rise from the horizon to the meridian, and it is the most widely used system in modern Western astrology.
- ModalityModality is the way a sign moves, and there are three: cardinal signs begin, fixed signs hold, and mutable signs adapt.
- Chart rulerThe chart ruler is the planet that rules the sign on the Ascendant, and classical astrology treats it as the significator of the person themselves.
- VertexThe vertex is the point where the ecliptic meets the prime vertical in the west, a calculated angle some astrologers read as a place of encounter.
- Aspect patternAn aspect pattern is a configuration of three or more planets whose aspects close into a shape, such as a grand trine, a T-square or a yod.
- Chart shapeA chart shape describes how the ten planets are distributed around the wheel as a whole, in the seven patterns Marc Edmund Jones named.
Dignity and condition
- Essential dignityEssential dignity is how well a planet is placed by sign, measured on a fixed classical scale of five tiers: domicile, exaltation, triplicity, term and face.
- DomicileDomicile is the sign a planet rules, where it acts most freely and where classical astrology considers it strongest by sign.
- ExaltationExaltation is a sign where a planet is honoured rather than at home, giving it a high but borrowed dignity: the Sun in Aries, the Moon in Taurus, Saturn in Libra.
- Detriment and fallDetriment is the sign opposite a planet's domicile and fall is the sign opposite its exaltation; both describe a planet working against the grain of the sign it occupies.
- TriplicityTriplicity is dignity by element: each of the four elements has rulers who lend a planet moderate support anywhere in that element's three signs.
- Term (bound)A term, also called a bound, is an unequal division of a sign, usually five per sign, each ruled by one of the five non-luminary planets.
- FaceA face is the ten-degree division of a sign in the dignity scheme, ruled in the Chaldean order, and it is the weakest of the five essential dignities.
- PeregrineA peregrine planet holds none of the five essential dignities in the sign it occupies, so it has no support of its own to draw on.
- AlmutenThe almuten of a place is the planet with the most weighted dignity there, counted across domicile, exaltation, triplicity, term and face, and the almuten of the whole chart is called the almuten figuris.
- Mutual receptionTwo planets are in mutual reception when each occupies a sign the other rules, an exchange that classical astrology reads as mutual assistance between them.
- Benefic and maleficClassical astrology sorts the planets by nature into benefics, Venus and Jupiter, and malefics, Mars and Saturn, with Mercury taking the character of whatever it is joined to.
- Planetary joyPlanetary joy is the house a planet is said to rejoice in, an early Hellenistic scheme giving each of the seven a place where its nature is most at home.
- Oriental and occidentalA planet is oriental when it rises before the Sun and occidental when it sets after it, a distinction classical astrology reads as a difference in how the planet acts.
- BesiegementBesiegement, also called enclosure, is a planet bracketed between the two malefics or the two benefics with no ray of the opposite kind breaking in.
Timing
- RetrogradeA planet is retrograde when it appears to move backwards through the zodiac from Earth, an effect of the two orbits passing rather than any change in the planet's motion.
- EphemerisAn ephemeris is a table of planetary positions for each day, traditionally listing where every body stood at the same hour, which is how charts were cast before computers.
- TransitA transit is the aspect a planet in the sky right now makes to a position in a birth chart, and it is the main way astrology describes timing.
- Void-of-course MoonThe Moon is void of course when it will make no further major aspect before leaving its current sign, a window traditional astrology treats as unfavourable for starting things.
- Planetary hourA planetary hour is one of twelve unequal divisions of daylight or of night, each ruled by a planet in the Chaldean order, which is why the days of the week carry planetary names.
- Solar returnA solar return is the chart cast for the moment the Sun comes back to its exact natal degree each year, read as a portrait of the year ahead.
- Annual profectionAnnual profection advances the Ascendant one whole sign for each year of life, so the house it reaches names the year's theme and its ruler becomes the lord of the year.
- FirdariaFirdaria is a Persian time-lord system that divides a life into fixed planetary periods in a set order, each period subdivided into seven sub-periods ruled by the other planets in turn.
- Zodiacal releasingZodiacal releasing is a Hellenistic time-lord technique that unfolds periods from a Lot, usually Spirit for career and Fortune for the body and circumstance, dividing a life into nested chapters.
- Secondary progressionSecondary progression moves the chart forward one day for each year of life, so the sky on your thirtieth day after birth describes your thirtieth year.
- Solar arc directionSolar arc direction moves every point in the chart forward by the same amount the Sun has progressed, roughly one degree for each year of life, so the whole chart advances together.
- StationA station is the moment a planet appears to stop before changing direction, either turning retrograde or turning direct, and traditional astrology reads a stationary planet as unusually emphatic.
- EclipseAn eclipse is a New or Full Moon that falls close enough to a lunar node for the three bodies to line up, so a solar eclipse hides the Sun and a lunar eclipse darkens the Moon.
- LunationA lunation is a New or Full Moon, the two points where the Moon meets or opposes the Sun, and the lunation cycle is the twenty-nine and a half days between one New Moon and the next.
- Electional astrologyElectional astrology chooses the moment to begin something, reading a future chart forward instead of reading a past one back.
- Via CombustaThe Via Combusta, the burned path, is the belt from about 15 degrees of Libra to about 15 degrees of Scorpio, which classical astrology marks as unfavourable ground for the Moon.
Two charts
- SynastrySynastry is the comparison of two birth charts, reading the aspects each person's planets make to the other's and the houses they fall into.
- Composite chartA composite chart is a single chart built from the midpoints between two people's planets, read as the chart of the relationship itself rather than of either person.
Classical medical astrology
- HylegThe hyleg is the chart's giver of life, the body chosen by rule from a short list of candidates, which classical medical astrology reads as the source of vitality.
- AlcochodenThe alcochoden is the planet that rules the hyleg's position, read in classical medical astrology as the one that gives the giver of life its quality and measure.
- TemperamentTemperament is the classical reading of a chart's balance of hot, cold, wet and dry, expressed as one of the four humours: choleric, sanguine, melancholic or phlegmatic.
Technique
- AntisciaAntiscia are points mirrored across the solstice axis, so two degrees that share the same day length are linked even when they form no ordinary aspect.
- Part of FortuneThe Part of Fortune, or Lot of Fortune, is a calculated point measured from the Ascendant by the distance between the Sun and Moon, and it is the best known of the classical lots.
- DispositorA planet's dispositor is the ruler of the sign it sits in, so a Mars in Cancer is disposited by the Moon, and following that chain is one of the oldest ways of reading a chart's structure.
- Horary astrologyHorary astrology answers a specific question from a chart cast for the moment the astrologer understood it, rather than from anyone's birth chart.
- Fixed starA fixed star is one of the stars proper, called fixed because it holds its place in the constellations while the planets wander among them.
- Hermetic lotA hermetic lot is a calculated point derived by measuring the arc between two planets and projecting it from the Ascendant, the best known being the Lot of Fortune.
- Prenatal lunationThe prenatal lunation is the New or Full Moon immediately before a birth, treated by Hellenistic astrology as a significant point of the nativity.
- DeclinationDeclination is a body's distance north or south of the celestial equator, the second coordinate that zodiacal longitude alone leaves out.
- Lunar mansionA lunar mansion is one of twenty-eight divisions of the Moon's monthly path, each roughly the distance it travels in a day, used across the Arabic, Indian and Chinese traditions.