Why was "tantrum" trending last week?
c.1600, insente, from French enceinte "pregnant" (12c.), from Late Latin incincta (source of Italian incinta), usually explained as "ungirt," from Latin in-, privative prefix (see in- (1)), + cincta, fem. of cinctus, past participle of cingere "to gird" (see cinch). Modern form is 18c., perhaps a reborrowing from French.