Rigid body

Physical object which does not deform when forces or moments are exerted on it

In physics, a rigid body, also known as a rigid object, is a solid body in which deformation is zero or negligible. The distance between any two given points on a rigid body remains constant in time regardless of external forces or moments exerted on it. A rigid body is usually considered as a continuous distribution of mass.

This keyword could refer to multiple things. Here are some suggestions: