noun
iroha order; traditional Japanese syllabary order
Refers to the ordering of kana based on the iroha poem, as opposed to the modern gojūon order. Often used in indexes, dictionaries, or lists that follow this traditional sequence.
See also: 五十音順
この辞書の索引はいろは順に並んでいる。
The index of this dictionary is arranged in iroha order.
いろは順と五十音順の違いを説明し
Please explain the difference between iroha order and gojūon order.
五十音順 is the modern standard kana ordering (a, i, u, e, o…), while いろは順 is the traditional ordering based on the iroha poem.
From いろは (iroha, the traditional ordering poem) + 順 (じゅん, order). The iroha poem itself is a well-known pangrammic Buddhist verse.