Word Origin & History
wiseacre
1595, partial translation of M.Du. wijssegger "soothsayer" (with no derogatory connotation), probably altered by association with M.Du. segger "sayer" from O.H.G. wizzago "prophet," from wizzan "to know," from P.Gmc. *wit "know." The depreciatory sense of "one who pretends to know everything" may have come through confusion with obsolete Eng. segger "sayer," which also had a sense of "braggart" (c.1440).