Meaning

noun (Old Testament) Adam's wife in Judeo-Christian mythology: the first woman and mother of the human race; God created Eve from Adam's rib and placed Adam and Eve in the Garden of Eden

noun the day before

noun the period immediately before something

originFrom a variant of the Middle English noun even (itself from Old English ǣfen), with a pre-1200 loss of the terminal '-n', which was mistaken for an inflection. See also the now archaic or poetic even (“evening”), from the same source. In medieval Europe, days were considered to extend from sunset to sunset rather than midnight to midnight, so the night before a holiday was considered part of it,…

Etymology from Wiktionary, CC BY-SA 3.0