1. The tendency of a body to float or to rise when submerged in a fluid.
  2. The power of a fluid to exert an upward force on a body placed in it.
  3. The ability to recover quickly from depression or discouragement.
  4. The property of maintaining a satisfactorily high level.

The emotion of Buoyancy is found in the Triple Heater meridian in the Fire element.

Definition from Dictionary by Merriam-Webster.