I attempted to dig into the meaning of the Japanese word for functor, 関手. https://ja.wikipedia.org/wiki/%E9%96%A2%E6%89%8B https://ja.wikipedia.org/wiki/%E9%96

I attempted to dig into the meaning of the Japanese word for functor, 関手. https://ja.wikipedia.org/wiki/%E9%96%A2%E6%89%8B https://ja.wikipedia.org/wiki/%E9%96%A2%E6%89%8B 関 - Checkpoint or barrier, for example at customs and borders; "bolt" for closing a door; to relate. (https://kanji.jitenon.jp/kanji/463.html https://kanji.jitenon.jp/kanji/463.html) 手 - Hand, method, to do something "by oneself" as in by own's own hands. (https://kanji.jitenon.jp/kanji/033.html https://kanji.jitenon.jp/kanji/033.html) So roughly/possibly "a method of relating". "Function" in Japanese is 関数. Same first character as functor, and the second one means "number". It's also written as 函数, which comes from the Chinese word for it. In the Chinese word for functor, 函子, the second character means "child".