noun Physics.
- the condition in which the apparent effect of gravity is zero, as in the case of a body in free fall or in orbit.
noun
- the state or condition of weightlessness
- The condition of real or apparent weightlessness occurring when any gravitational forces acting on a body meet with no resistance so the body is allowed to accelerate freely. Bodies in free fall (including trajectories like orbits) experience zero gravity; bodies at rest on the Earth’s surface do not, since they are subject to the counterforce of the surface supporting them.