Reference library
Zodiac Glossary
Plain-language definitions for the most common zodiac, astrology and astronomy terms.
Sun sign
The astrological sign occupied by the Sun in a birth chart.
Zodiac
A band or coordinate framework around the ecliptic, interpreted differently in astrology and astronomy.
Ecliptic
The Sun’s apparent annual path across the sky as seen from Earth.
Cusp
A boundary between astrological signs or houses.
Element
One of four symbolic groups in Western astrology: fire, earth, air and water.
Modality
One of three sign qualities: cardinal, fixed and mutable.
Ruling planet
A planet traditionally associated with a zodiac sign.
Birth chart
An astrological diagram representing celestial positions for a specific time and place.
Constellation
An officially defined region of the sky; in casual use, also a recognizable star pattern.