Where does “灰貝” come from?

灰貝 (Japanese) comes from Japanese 貝, from Old Japanese かい.

灰貝 (Japanese): blood cockle, blood clam an Asian species of bivalve resembling the cockle (Tegillarca granosa)

Definitions

  1. blood cockle, blood clam an Asian species of bivalve resembling the cockle (Tegillarca granosa)

Ancestry of “灰貝”, step by step

灰貝 traces back through two separate lines of ancestry.

via Japanese 貝

StepLanguageWordMeaning
1Japanese貝a shellfish
2Old Japaneseかい—

via Japanese 灰

StepLanguageWordMeaning
1Japanese灰ash
2Middle Chineseかい—
Every word from Old Japanese かい →Every word from Japanese 貝 →