INDEFEASIBLE Meaning of INDEFEASIBLE in English [ ˌɪndɪ'fi:zɪb(ə)l ]■ adjective chiefly Law & Philosophy not subject to being lost, annulled, or overturned.Derivativesindefeasibility nounindefeasibly adverb Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004