Where does “サ行変格活用” come from?

サ行変格活用 (Japanese) comes from Japanese 変格活用, from Japanese 変格, from Japanese 変, from Middle Chinese 變.

サ行変格活用 (Japanese): a verbal conjugation class in which the verb stem...

Definitions

  1. a verbal conjugation class in which the verb stem...

Ancestry of “サ行変格活用”, step by step

サ行変格活用 traces back through two separate lines of ancestry.

via Japanese 変格活用

StepLanguageWordMeaning
1Japanese変格活用irregular conjugation
2Japanese変格irregularity; irregular conjugation; translative...
3Japanesea change
4Middle Chinese

via Japanese サ行

StepLanguageWordMeaning
1Japaneseサ行"sa"-row
Every word from Middle Chinese Every word from Japanese Every word from Japanese 変格
サ行変格活用 — Etymology, Origin & Word History | Etymology Explorer