Is it ensure, insure, or assure?
late 14c., "to receive," from Middle French excepter (12c.), from Latin exceptus, past participle of excipere "take out," from ex- "out" (see ex-) + capere "to take" (see capable). Meaning "to leave out" is from 1510s. Related: Excepted; excepting. Adjectival function led to use as a preposition, conjunction (late 14c.).