Module 7 of 7 · Lesson 23 of 24
📖 Western Astrology Glossary
New astrology terms can be confusing at first. This glossary defines every key term used across the Learning Center in plain language, with links to the full lesson for each concept.
A — Terms starting with A
- Angular Houses
- The 1st, 4th, 7th, and 10th houses — considered the most powerful and action-oriented houses in a birth chart, tied to identity, home, partnership, and career.
- Applying Aspect
- An aspect that is still moving toward its exact angle, meaning its influence is building rather than fading.
- Ascendant (Rising Sign)
- The zodiac sign that was rising on the eastern horizon at the exact moment of birth; it shapes first impressions and begins the house system.
- Aspect
- An angular relationship between two planets, such as a conjunction, square, or trine, that describes how their energies interact.
B — Terms starting with B
- Big 3
- A person's Sun, Moon, and Rising sign together — the three most individually defining placements in a birth chart.
- Big 6
- The Big 3 plus Mercury, Venus, and Mars — six placements that give a fuller picture of personality, communication, love, and drive.
C — Terms starting with C
- Cadent Houses
- The 3rd, 6th, 9th, and 12th houses, associated with learning, adjustment, and transition between life phases.
- Cardinal
- A modality describing signs that initiate action and lead change: Aries, Cancer, Libra, and Capricorn.
- Chiron
- A small planetoid known as the wounded healer, associated with deep emotional wounds and the wisdom gained from healing them.
- Composite Chart
- A single chart built from the midpoints between two people's planets, representing a relationship as its own entity.
- Conjunction
- An aspect where two planets sit at (or very near) the same degree of the zodiac, fusing their energies together.
- Cusp
- The exact degree marking the boundary between one house or zodiac sign and the next.
E — Terms starting with E
- Element
- One of four groups — Fire, Earth, Air, or Water — describing a zodiac sign's core temperament.
- Ephemeris
- A table or dataset listing the positions of the planets at given dates and times, used to calculate charts.
F — Terms starting with F
- Fixed
- A modality describing signs that stabilize and sustain: Taurus, Leo, Scorpio, and Aquarius.
H — Terms starting with H
- Houses
- The 12 divisions of a birth chart, each governing a different area of life, from identity to career to relationships.
L — Terms starting with L
- Lunar Return
- A chart cast for the moment the Moon returns to its natal degree, occurring roughly every month.
M — Terms starting with M
- Midheaven (MC)
- The highest point of a birth chart, marking career, public reputation, and life direction; it sits at the top of the 10th house.
- Modality
- One of three categories — Cardinal, Fixed, or Mutable — describing how a sign approaches change and action.
- Mutable
- A modality describing adaptable, flexible signs: Gemini, Virgo, Sagittarius, and Pisces.
N — Terms starting with N
- Natal Chart
- A map of the exact positions of the planets at the moment and place of a person's birth; also called a birth chart.
- Node (North/South Node)
- Two symbolic points describing karmic direction (North Node) and past patterns or comfort zones (South Node).
O — Terms starting with O
- Opposition
- An aspect where two planets sit roughly 180° apart, creating polarity and a need for balance.
- Orb
- The number of degrees an aspect deviates from its exact angle; a smaller orb means a stronger aspect.
P — Terms starting with P
- Personal Planets
- The Sun, Moon, Mercury, Venus, and Mars — the fastest-moving planets, which shape individual personality most distinctly.
- Placidus
- The most widely used Western house system, which divides a chart into houses of unequal size based on time and latitude.
Q — Terms starting with Q
- Quincunx
- An awkward 150° aspect that requires creative adjustment between two very different planetary energies.
R — Terms starting with R
- Retrograde
- The apparent backward motion of a planet as seen from Earth, often read as a time for review and reflection.
S — Terms starting with S
- Sextile
- A cooperative 60° aspect that creates opportunity, though it usually requires some initiative to activate.
- Solar Return
- A chart cast for the exact moment the Sun returns to its natal degree each year, close to a person's birthday.
- Square
- A tense 90° aspect that creates friction and motivates action and growth.
- Stellium
- A cluster of three or more planets in the same sign or house, indicating a strong concentration of energy in that area.
- Sun Sign
- The zodiac sign the Sun occupied at the moment of a person's birth; commonly called a star sign.
- Synastry
- The technique of comparing two birth charts to understand the dynamics and compatibility between two people.
T — Terms starting with T
- Transit
- The current position of a moving planet compared to a natal chart, used to time events and understand current themes.
- Trine
- A harmonious 120° aspect where two planets support each other with natural ease.
- Tropical Zodiac
- The zodiac system used in Western astrology, aligned to the Earth's seasons rather than the fixed constellations.
Z — Terms starting with Z
- Zodiac Sign
- One of 12 thirty-degree segments of the ecliptic, each describing a distinct personality archetype.
Try It Yourself
Put these terms into practice with these free calculators:
Related Lessons
Introduction to Western Astrology
Discover what Western astrology is, how it developed over thousands of years, and how astrologers use the tropical zodiac, planets, houses, and aspects to interpret birth charts.
Read Lesson →Western Astrology FAQ
Fast answers to the most common Western astrology questions.
Read Lesson →Understanding Your Natal (Birth) Chart
Learn what a natal chart is, how it is calculated, and how to begin interpreting your unique astrological blueprint.
Read Lesson →Western Astrology Glossary — Frequently Asked Questions
How many terms are in this glossary?
This glossary currently covers 38 essential Western astrology terms, and it grows as new lessons are added to the Learning Center.
Are these definitions simplified?
Yes — each definition is written in plain language for beginners. For a full explanation of any term, follow the linked lesson for that concept.
What if a term isn't listed here?
The glossary covers the core vocabulary used throughout this Learning Center. If a term is missing, check the FAQ page or the relevant lesson for more context.
Is this glossary specific to Western astrology?
Yes — all terms here reflect Western (tropical) astrology conventions. Some terms, like element and modality, are used differently or not at all in other astrological traditions such as Vedic astrology.