ICHTHYOSIS Meaning of ICHTHYOSIS in English [ ˌɪkθɪ'əʊsɪs ]■ noun Medicine a congenital skin condition which causes the epidermis to become dry and horny like fish scales.Derivativesichthyotic adjective Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004