Is it ensure, insure, or assure?
early 13c., "state of being human," from man (n.) + -hood. Meanings "state of being an adult male," also "manliness," are from late 14c. Similar words in Old English were less explicitly masculine; cf. manscipe "humanity, courtesy," literally "man-ship;" mennisclicnes "state of man, humanity, humaneness, human nature." The more "manly" word was werhad "male sex, virility, manhood" (see first element in werewolf).