early 14c., "whalebone," from Old French balaine "whale, whalebone" (12c.), from Latin ballaena, from Greek phallaina "whale," which is apparently phallos "swollen penis" (perhaps because of a whale's body shape) with a fem. suffix. If so, it is from PIE root *bhel- (2) "to blow, swell." The b- (instead of -p-) for ph- substitution shows it entered Latin through a third language (Klein suggests Illyrian).