LITHIASIS Meaning of LITHIASIS in English [ lɪ'θʌɪəsɪs ]■ noun Medicine the formation of stones in an internal organ such as the kidney or gall bladder.OriginC17: from med. L., based on Gk lithos 'stone'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004