[diegoperini]

> In the case of "functor", I also find the Chinese (函子) more obvious than the Japanese (関手) or English.

If not too much to ask, can you please explain how those non-latin characters form the meaning for the word "functor"? In my native tongue (Turkish), we borrow the word "functor" without applying a translation to it, thus it becomes one of those things you simply memorize and move on.

Do these Chinese and Japanese words form a meaning similar to something like "function-izer" or "function+abler" or something else?

[dwohnitmok]

函子 should probably be analyzed as an abbreviation of "函数" (function) + "子" ("essence of" or "atomic unit of"). This meaning of "子" is the predominant one when used in technical contexts. See molecule "分子" （unit of separation） atom "原子" (the original/fundamental unit) electron "电子" (unit of electricity) or monad "单子" (essence/unit of oneness) where the second character is third tone not neutral. Many of these originate in Japanese and are re-borrowed back into Chinese, but that's a story for another time.

A sibling comment points out that 子 can mean child. This is the original, ancient meaning of the character. This usage is still productive in modern Chinese (usually to mean sons), but the previous examples are examples of how the meaning has undergone some transformations to form derived, related meanings. The original meaning can also be found in technical contexts. Examples of this are 子集 (child + set = subset) and again 分子 (fraction + child = numerator) with the counterpart 分母 (fraction + mother = denominator). This is not how I scan functor 函子 though.

In the Chinese programming community, you'll usually just see the English words "Functor" and "Monad" used. I wouldn't be surprised if some Chinese programmers familiar with "Functor" do not recognize "函子." I've only ever seen 函子 used in math articles and occasional FP tutorials (and even then, given how dominant English is, it is often glossed by "Functor").

[lioeters]

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

関 - Checkpoint or barrier, for example at customs and borders; "bolt" for closing a door; to relate. (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)

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".