Pertaining to an equinox, or the equinoxes, or to the time of equal day and night; as, the equinoctial line.

Pertaining to the regions or climate of the equinoctial line or equator; in or near that line; as, equinoctial heat; an equinoctial sun.

Pertaining to the time when the sun enters the equinoctial points; as, an equinoctial gale or storm, that is, one happening at or near the time of the equinox, in any part of the world.

the great circle on the celestial sphere midway between the celestial poles

relating to the vicinity of the equator

relating to an equinox (when the lengths or night and day are equal)

(Q). Celestial equator as projected by the earth's equatorial plane.

relating to or based on the equator, or relating to the equinox.