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."

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"antly.

Origin: From Buoy, & i.

(01 Mar 1998)