BUOYANCY

buoyancy, irrepressibility

(noun) irrepressible liveliness and good spirit; “I admired his buoyancy and persistent good humor”

buoyancy

(noun) the tendency to float in water or other liquid

airiness, buoyancy

(noun) the property of something weightless and insubstantial

buoyancy, perkiness

(noun) cheerfulness that bubbles to the surface

Source: WordNet® 3.1

Etymology

Noun

buoyancy (countable and uncountable, plural buoyancies)

(physics) The upward force on a body immersed or partly immersed in a fluid.

The ability of an object to stay afloat in a fluid.

(by extension) Resilience or cheerfulness.

Source: Wiktionary

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)

Definition: 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.

Source: Webster’s Unabridged Dictionary 1913 Edition