BUOYANCY
Buoy"an*cy, n.; pl. Buoyancies (.
1. The property of floating on the surface of a liquid, or in a fluid, as in the atmosphere; specific lightness, which is inversely as the weight compared with that of an equal volume of water.
2. (Physics)
Defn: The upward pressure exerted upon a floating body by a fluid, which is equal to the weight of the body; hence, also, the weight of a floating body, as measured by the volume of fluid displaced. Such are buoyancies or displacements of the different classes of her majesty's ships. Eng. Cyc.
3. Cheerfulness; vivacity; liveliness; sprightliness; — the opposite of Ant: heaviness; as, buoyancy of spirits.
BUOYANT
Buoy"ant, a. Etym: [From Buoy, v. t. & i.]
1. Having the quality of rising or floating in a fluid; tending to rise or float; as, iron is buoyant in mercury. "Buoyant on the flood." Pope.
2. Bearing up, as a fluid; sustaining another body by being specifically heavier. The water under me was buoyant. Dryden.
3. Light-hearted; vivacious; cheerful; as, a buoyant disposition; buoyant spirits. — Buoy"ant*ly, adv.
BUPRESTIDAN
Bu*pres"ti*dan, n. Etym: [L. buprestis, Gr. (Zoöl.)