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1. Cheerfulness that bubbles to the surface
   - perkiness
    
2. The property of something weightless and insubstantial
   - airiness
    
3. The tendency to float in water or other liquid
    
4. Irrepressible liveliness and good spirit
   "I admired his buoyancy and persistent good humour";
   - irrepressibility

Derived forms: buoyancies

Type of: blitheness, cheerfulness, inclination, life, lightness, liveliness, spirit, sprightliness, tendency, weightlessness

Encyclopedia: Buoyancy