mid15c., from Latin inversus, past participle of invertere (see invert). Related: Inversely. As a noun, 1680s, from the adjective.
inverse Adjective (ĭnvûrs') Relating to a mathematical operation whose nature or effect is the opposite of another operation. For example, addition and subtraction are inverse operations, as are multiplication and division. Noun (ĭn'vûrs')
