Where does “長亀” come from?

長亀 (Japanese) comes from Japanese 長, from Middle Chinese 長.

長亀 (Japanese): a leatherback sea turtle

Definitions

  1. a leatherback sea turtle

Ancestry of “長亀”, step by step

長亀 traces back through two separate lines of ancestry.

via Japanese 長

StepLanguageWordMeaning
1Japanese長chief, head, leader; strong point; major
2Middle Chinese長—

via Japanese 亀

StepLanguageWordMeaning
1Japanese亀a tortoise or turtle; a drunkard; a 家紋 with...
2Middle Chinese龜—
Every word from Middle Chinese 長 →Every word from Japanese 長 →
長亀 — Etymology, Origin & Word History | Etymology Explorer