Available Definitions:
1) n. - A float; esp. a floating object moored to the bottom, to mark a channel or to point out the position of something beneath the water, as an anchor, shoal, rock, etc.
2) v. t. - To keep from sinking in a fluid, as in water or air; to keep afloat; -- with up.
3) v. t. - To support or sustain; to preserve from sinking into ruin or despondency.
4) v. t. - To fix buoys to; to mark by a buoy or by buoys; as, to buoy an anchor; to buoy or buoy off a channel.
5) v. i. - To float; to rise like a buoy.