Where does “カ行変格活用” come from?

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

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

Definitions

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

Ancestry of “カ行変格活用”, step by step

カ行変格活用 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...
3Japanese変a change
4Middle Chinese變—

via Japanese カ行

StepLanguageWordMeaning
1Japaneseカ行"ka"-row
Every word from Middle Chinese 變 →Every word from Japanese 変 →Every word from Japanese 変格 →