IDEMPOTENT Meaning of IDEMPOTENT in English [ ˌʌɪdɛm'pəʊt(ə)nt , ʌɪ'dɛmpət(ə)nt ]■ noun Mathematics an element of a set which is unchanged in value when operated on by itself.OriginC19: from L. idem 'same' + potent 1 . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004