yes·ter·eve I. \ˈyestə|rēv\adverb oryes·ter·e·ven\-vən\; oryes·ter·eve·ning\-vniŋ\ Etymology:yester- (as in yesterday) + eve or even or evening archaic: on the evening of yesterday II. noun oryestereven\“\; oryesterevening\“\ archaic: the evening of yesterday : the evening last past