/ Dictionary / Index E equinox: Meaning and Definition of Find definitions for: e•qui•nox Pronunciation: (ē'kwu-noks", ek'wu-), [key] — n. the time when the sun crosses the plane of the earth's equator, making night and day of approximately equal length all over the earth and occurring about March 21and September 22 either of the equinoctial points. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: equinox (Thesaurus) equinoctial year equi NP deletion Related Content Daily Word Quiz: pristine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language