MYDRIASIS Meaning of MYDRIASIS in English [ ˌmɪdrɪ'eɪsɪs , mɪ'drʌɪəsɪs ]■ noun Medicine dilation of the pupil of the eye.OriginC19: via L. from Gk mudriasis . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004