INDUSIUM Meaning of INDUSIUM in English [ ɪn'dju:zɪəm ]■ noun ( plural indusia ) chiefly Botany a thin membranous covering, especially a shield covering a sorus on a fern frond.OriginC18: from L., lit. 'tunic'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004