buoyant force is the result of the displacement of the fluid an object is in.

if a fluid is displaced by the volume of an object, the weight of the fluid being displaced is pushing up on that object

Depending upon the field of science, at least 3 different meanings exist -

Displacement is the shortest distance from a starting point to an end point. For example, if you run 150 metres along a road, to a shop, your displacement will be 150 metres. If you run back to your original starting point, your displacement will be 0 metres. If you then ran 30 metres in the opposite direction. Your displacement would be 30 metres.

Displacement is the volume of a fluid that is moved (displaced) when an object is submersed within the fluid. Fluid displacement is used to measure the volume of an object of irregular shape. The fluid is measured before and after displacement to determine the object volume.

In psychology, displacement refers to an unconscious defense mechanism where the mind redirects thoughts of a dangerous situation to a less dangerous or safe alternative.

positive displacement pump

by measuring it's weight and it's surface tension.

a solid pushes water up and out when placed inside