1. (n.) The property of floating on a liquid, or in a gas\, as in the atmosphere; specific lightness, which is inversely as the weight compared with that of an equal volume of water.

2. (n.) 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.

3. (n.) Cheerfulness; vivacity; liveliness; sprightliness; -- the opposite of heaviness; as, buoyancy of spirits.

adaptability airiness ascent bounce bounciness breeziness bubbliness buoyance carefreeness chirpiness daintiness debonairness delicacy downiness effervescence elasticity ethereality extensibility exuberance flexibility floatability fluffiness foaminess frothiness gentleness give gossameriness jauntiness lack of weight levitation levity light heart lightheartedness lightness lightsomeness liveliness perkiness pertness rebound resilience resiliency responsiveness snap softness spring springiness stretch stretchability stretchiness tenderness tone tonicity tonus unheaviness volatility weightlessness yeastiness