- The total range of variation of a quantity like the height of a wave, the magnitude of a variable star, or any other measured amount. In astronomy, amplitude measurements are most often made of light curves, the graphs which show how the radiation received from stars and other astronomical objects varies with time.
- In sound or vibration, the maximum variation from the mean position.
- The extent of the up and down movements of a fluctuating economic variable; that is, the difference between the highest and lowest values of the variable. See destabilizing speculation.
- In a wave or other periodic phenomenon, the maximum absolute value of the displacement from a reference position, such as zero.
- noun a measurement of radio waves, describing the distance of the waves upwards or downwards from the centre point.
- noun the degree of height a rider can attain above the lip of a pipe