1.Definition: cheerfulness that bubbles to the surface

Related Noun(s):perkiness

Category: Feelings

2.Definition: irrepressible liveliness and good spirit

"I admired his buoyancy and persistent good humor"

Related Noun(s):irrepressibility

Category: General

3.Definition: the property of something weightless and insubstantial

Related Noun(s):airiness

Category: General

4.Definition: the tendency to float in water or other liquid

Category: General