(of sound in a specified direction) the average rate of flow of sound energy, usually in watts, for one period through unit area at right angles to the specified direction I
4.
(geology) Also called earthquake intensity. a measure of the size of an earthquake based on observation of the effects of the shock at the earth's surface. Specified on the Mercalli scale See Mercalli scale, Richter scale
Word Origin and History for intensity
n.
formed in English 1660s from intense + -ity. Earlier was intenseness (1610s). Sense of "extreme depth of feeling" first recorded 1830.