English Dictionary

Having the quality of rising or floating in a fluid; tending to rise or float; as, iron is buoyant in mercury.
Source : opted (20905)  - auto

Bearing up, as a fluid; sustaining another body by being specifically heavier.
Source : opted (20906)  - auto

Light-hearted; vivacious; cheerful; as, a buoyant disposition; buoyant spirits.
Source : opted (20907)  - auto