c.1200, in sailing, from Old French lof "spar," or some other nautical device, "point of sail," also "windward side," probably from Germanic (compare Middle Dutch lof "windward side of a ship" (Dutch loef), which might also be the direct source of the English word), from Proto-Germanic *lofo (cognates: Old Norse lofi, Gothic lofa "palm of the hand," Danish lab, Swedish labb "paw"), from PIE *lep- "to be flat" (see glove). As a verb from late 14c., from the noun.