Meaning

noun bright-colored; a float attached by rope to the seabed to mark channels in a harbor or underwater hazards

verb float on the surface of water

verb keep afloat

originFrom Middle English boy, boye, from Middle Dutch boeye (“float, buoy”), from Old French boue (“piece of wood or cork that floats above an anchor to indicate where it is anchored”) (modern French bouée), ultimately from Frankish *baukn (“beacon”), from Proto-Germanic *baukną. Doublet of beacon. Alternatively, and perhaps less likely (due to the unexplained shift in meaning), from Middle Dutch…

Etymology from Wiktionary, CC BY-SA 3.0