Upthrust (noun)

An upward force exerted on a body submerged in a fluid, equal to the weight of the fluid displaced.

Origin:

Late 19th century; earliest use found in transactions of the royal society of south australia. from up- + thrust.

Examples:

1. The upthrust on the ship allowed it to float on the surface of the water.
2. The upthrust of the balloon helped it rise into the sky.
3. The upthrust of the diving board helped the athlete execute a successful dive.
4. The upthrust on the boat was determined by the weight of the water it displaced.
5. The upthrust of the iceberg was measured to determine its stability.