IMPUISSANT Meaning of IMPUISSANT in English [ ɪm'pju:ɪs(ə)nt , -'pwi:- , -'pwɪs- ]■ adjective literary unable to take effective action; powerless.Derivativesimpuissance noun Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004