Equinoctial

Alternative forms

 * æquinoctial (archaic)

Adjective

 * of, or relating to an equinox
 * 1)  of, or relating to the celestial or terrestrial equator

Derived terms

 * equinoctial circle
 * equinoctial point
 * equinoctial year
 * equinoctially

Noun

 * 1) the great circle midway between the celestial poles; the celestial equator
 * 2)  the terrestial equator.