ふりょく浮力furyoku
1.

The upward force experienced by an object submerged in a fluid, which acts in opposition to gravity, equal to the weight of the fluid displaced by the object.

2.

The pressure exerted by a fluid that pushes an object upwards when it is partially or fully immersed, allowing it to float or rise.

Example:

塩水の方が淡水よりも浮力が大きい。