late 14c., "wanting in self restraint," from Old French incontinent, from Latin incontinentem (nominative incontinens) "incontinent, immoderate, intemperate," from in- "not, opposite of" (see in- (1)) + continens (see continent). Originally chiefly of sexual appetites; sense of "unable to control bowels or bladder" first attested 1828.
incontinent in·con·ti·nent (ĭn-kŏn'tə-nənt)
Lacking normal voluntary control of excretory functions.
Lacking sexual restraint; unchaste.