[noun](phonology,orthography,grammar) the first row of the 五十音図(literally “table of the fifty sounds”), consisting of the five kana あ/ア(a), い/イ(i), う/ウ(u), え/エ(e) and お/オ(o)
Alternative spelling ア行
(This term, 阿行, is an alternative spelling of the above term.)