from Old English æfnung "the coming of evening, sunset, time around sunset," verbal noun from æfnian "become evening, grow toward evening," from æfen "evening" (see eve). As a synonym of even (n.) in the sense "time from sunset to bedtime," it dates from mid-15c. and now entirely replaces the older word in this sense. Another Old English noun for "evening" was cwildtid.
updated on September 20, 2014