A
- Angles
- The four chart points created by the horizon and meridian: ascendant, descendant, Midheaven, and Imum Coeli.
- Applying aspect
- An aspect moving toward exactness. Traditional practice often treats applying contacts as developing or especially active.
- Ascendant
- The zodiac degree rising on the eastern horizon at a specific time and location. It begins the first house in many house systems.
- Aspect
- An angular relationship between chart factors, interpreted as a way their functions exchange energy.
B
- Birth chart
- A map of planetary positions and local angles for a particular moment and place, usually the moment of birth.
C
- Cadent houses
- Houses 3, 6, 9, and 12. They traditionally distribute, adapt, and contextualize what angular houses initiate.
- Cardinal signs
- Aries, Cancer, Libra, and Capricorn. Cardinal modality initiates a new phase of its element.
- Chart ruler
- The planet ruling the ascendant sign. Its placement connects the ascendant’s approach to a particular part of the chart.
- Conjunction
- An aspect near 0 degrees that concentrates two planetary functions in the same region of the zodiac.
- Cusp
- A boundary or degree beginning a house. A sign boundary is an ingress, not a blended personality category.
D
- Decan
- One of three ten-degree divisions of a zodiac sign. Exact solar longitude is needed to identify a Sun decan reliably.
- Degree
- One of 360 divisions of the zodiac circle. Each of the twelve signs contains 30 degrees.
- Descendant
- The zodiac degree setting on the western horizon, opposite the ascendant, and associated with the seventh-house angle.
- Dispositor
- The planet ruling the sign occupied by another planet. It describes where and how that placement obtains direction.
E
- Element
- Fire, Earth, Air, or Water. Elements describe broad symbolic temperaments and processing styles.
- Ephemeris
- A table or computational dataset giving astronomical positions for specific dates and times.
F
- Fixed signs
- Taurus, Leo, Scorpio, and Aquarius. Fixed modality sustains, concentrates, and stabilizes its element.
H
- House
- One of twelve local divisions of a chart associated with fields of experience. Houses require birth time and place.
- House ruler
- The planet ruling the sign on a house cusp. Its placement links that house’s topics to another chart location.
I
- Imum Coeli
- The lower meridian angle, often called the IC, associated with roots, private foundations, and the fourth-house axis.
- Ingress
- The astronomical moment a planet enters a new zodiac sign.
M
- Midheaven
- The upper meridian point, often called the MC, associated with public direction and culmination.
- Modality
- Cardinal, Fixed, or Mutable. Modality describes whether a sign initiates, sustains, or adapts.
- Mutable signs
- Gemini, Virgo, Sagittarius, and Pisces. Mutable modality adapts, translates, and prepares transition.
N
- Natal astrology
- The branch of astrology interpreting a chart cast for the moment and place of birth.
O
- Orb
- The allowed distance from an aspect’s exact angle. Astrological traditions and practitioners use different orb rules.
- Opposition
- An aspect near 180 degrees that places two functions across a polarity requiring balance and awareness.
P
- Planetary return
- The time when a planet returns to approximately the same zodiac longitude it occupied in the natal chart.
- Polarity
- A classification of signs as Yang or Yin, describing symbolic direction of energy rather than gender or value.
- Progression
- A symbolic timing technique that advances the natal chart according to a defined correspondence, such as one day for one year.
R
- Retrograde
- Apparent backward motion against the zodiac from Earth’s viewpoint. Natal interpretation varies by planet and tradition.
S
- Sect
- A traditional distinction between day and night charts that helps evaluate planetary roles and condition.
- Separating aspect
- An aspect moving away from exactness after its closest contact.
- Sextile
- An aspect near 60 degrees associated with cooperative opportunity that benefits from participation.
- Sidereal zodiac
- A zodiac framework tied to stellar reference points and adjusted through an ayanamsha.
- Sign
- One of twelve equal 30-degree divisions of the zodiac, interpreted as a style through which planets operate.
- Solar return
- A chart cast for the moment each year when the Sun returns to its natal longitude.
- Square
- An aspect near 90 degrees associated with friction, action, and the need for adjustment.
- Stellium
- A concentration of several planets in one sign or house. Definitions vary, so the planets and degrees should be stated.
- Succedent houses
- Houses 2, 5, 8, and 11. They traditionally consolidate and develop what angular houses initiate.
- Synastry
- A relationship technique comparing two natal charts through interchart aspects and house overlays.
T
- Transit
- The current or selected-time position of a planet compared with a natal chart or another reference chart.
- Trine
- An aspect near 120 degrees associated with flow, continuity, and capacities that may operate easily.
- Tropical zodiac
- A zodiac framework anchoring 0 degrees Aries to the March equinox and the cycle of seasons.
W
- Whole sign houses
- A house system in which the entire rising sign becomes the first house and each following sign forms the next house.
Z
- Zodiac
- A coordinate band along the ecliptic divided by astrology into twelve equal signs.