PERIODIC ACID Meaning of PERIODIC ACID in English [ ˌpə:rʌɪ'ɒdɪk ]■ noun Chemistry a hygroscopic solid acid with strong oxidizing properties.OriginC19: from sense 2 of per- + iodic acid . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004