Is it ensure, insure, or assure?
"check in growth, dwarf," 1650s, verb use of Middle English adjective stunnt "foolish," from Old English stunt "short-witted, foolish" (cf. stuntspræc "foolish talk"), from Proto-Germanic *stuntaz (cf. Old Norse stuttr "short"), from the root of stump. Related: Stunted; stunting.
"feat to attract attention," 1878, American English college sports slang, of uncertain origin. Speculated to be a variant of colloq. stump "dare, challenge" (1871), or of German stunde, literally "hour." The movie stunt man is attested from 1930.
Something very attractive or impressive, esp a good-looking woman (1847+)