Answer: buoyance

AnswerCrossword Clue
BUOYANCECheerfulness.
BUOYANCEWhat makes a lifesaver float
buoyancelightness or resilience of spirit; cheerfulness
buoyancethe tendency to float, also BUOYANCY
buoyancethe power to float or rise in a fluid; relative lightness
buoyancethe power of supporting a body so that it floats; upward pressure exerted by the fluid in which a body is immersed