国語仮名遣い
Meanings
1
historical kana orthography for native Japanese words
Refers to the traditional kana spelling system used for native Japanese vocabulary (as opposed to Sino-Japanese words). Often discussed in contrast to 字音仮名遣い (kana orthography for Sino-Japanese words) and modern kana usage.
In historical kana orthography for native words, 言ふ is written as いふ, not いう.
We learned about historical kana orthography for native words in classical Japanese class.