[noun](phonology,orthography,grammar) the first and highest-graded column of the 五十音図(literally “table of the fifty sounds”), consisting of the ten kana あ/ア(a), か/カ(ka), さ/サ(sa), た/タ(ta), な/ナ(na), は/ハ(ha), ま/マ(ma), や/ヤ(ya), ら/ラ(ra) and わ/ワ(wa)
Alternative spelling ア段
(This term, 阿段, is an alternative spelling of the above term.)