gill: English has three separate words gill. The oldest, gill ‘ravine’ [11], was borrowed from Old Norse gil, a word of unknown ancestry. Gill ‘fishes’ breathing organ’ [14] probably also comes from an Old Norse *gil, never actually recorded, but deduced from modern Swedish gäl and Danish gjælle ‘gill’. It may well go back to a prehistoric Indo-European source which also produced Greek kheilos ‘lip’. Gill ‘quarter of a pint’ [14] comes via Old French gille from medieval Latin gillo ‘water-pot’. [gill etymology, gill origin, 英语词源]