Beginner Astrology Glossary: 20 Terms You’ll See Everywhere
Astrology has its own vocabulary, and most explanations assume you already know it. Here are the twenty terms that come up constantly, in plain language, so you can bookmark this instead of looking each one up separately.
The basics
Natal chart — a map of the sky at your exact moment and place of birth. Also called a birth chart.
Sun sign — the sign the sun occupied when you were born. What people usually mean by “your sign.”
Moon sign — the sign the moon occupied at your birth. Associated with emotional life.
Rising sign / Ascendant — the sign on the eastern horizon at your birth. Associated with outward manner. Requires an accurate birth time.
Big three — shorthand for sun, moon and rising together.
Structure of the chart
House — one of twelve divisions of the chart, each representing an area of life.
Aspect — the angular relationship between two planets, read as how they interact.
Element — fire, earth, air or water. Each sign belongs to one.
Modality — cardinal, fixed or mutable. Describes a sign’s general approach to action and change.
Ruling planet — the planet traditionally associated with governing a particular sign.
Common aspect types
Conjunction — two planets at the same point, read as blended energy.
Trine — an easy, supportive angle between two planets.
Square — a tense angle, read as productive friction.
Opposition — planets directly across the chart, read as a pull between two needs.
Practice and technique
Synastry — comparing two people’s charts against each other, most often for relationships.
Transit — the current position of a planet in the sky, compared against your natal chart.
Retrograde — when a planet appears to move backward from Earth’s perspective. An optical effect, not literal reverse motion.
Ephemeris — a table listing planetary positions for every date, used to calculate charts before software existed.
Reading terms
Placement — general term for any planet’s position by sign and house.
Stellium — three or more planets clustered in the same sign or house.
Chart ruler — the ruling planet of your rising sign, often treated as especially significant.
Put it to use
Reading about these terms in the abstract only goes so far. Generate your own chart with a birth chart calculator and match each term against something real in front of you — find your stellium if you have one, check your chart ruler, look at one aspect involving your sun.
Once the vocabulary makes sense, this guide to what a birth chart actually says about you is the natural next read.
Vocabulary sticks a lot faster when it is attached to your own chart instead of someone else’s example.