idempotent Syllabification: (i·dem·po·tent)Pronunciation: /ˈīdemˌpōtənt/ MathematicsDefinition of idempotent adjective denoting an element of a set that is unchanged in value when multiplied or otherwise operated on by itself. noun an idempotent element. Origin: late 19th century: from Latin idem 'same' + potent1idempotent in other Oxford dictionaries Definition of idempotent in the British & World English dictionary