A body is said to be in resonance when it is affected by a force applied with a certain frequency, the resonant frequency, at which the body is seriously perturbed from equilibrium: An example of resonance in astronomy is provided by the Kirkwood gaps.

The use of a nuclear magnetic resonance spectrometer to produce electronic images of specific atoms and molecular structures in solids; especially, human cells, tissues, and organs.

A diagnostic test that uses a strong magnet to view tissues in the body and displays them in a series of "slices."