c. 1300 (intransitive); mid-14c. (transitive), from Old Norse væla "to lament," from væ "woe" (see woe). Of jazz musicians, "to play very well," attested from 1955, American English slang (wailing "excellent" is attested from 1954). Related: Wailed; wailer.[wail etymology, wail origin, 英语词源]