Tokei (時計 - Clock/Watch)

A tokei (時計 - clock/watch) is very important to our lives.

Tokei is composed of two kanji: 時 and 計.

Since 時 means "time" and 計 means "measuring," you may think it is reasonable that the composition expresses a clock/watch.

However, the kanji 時 doesn't have the reading of to (と).

Originally, tokei was written as 土圭, and it meant a latitude measuring instrument or a sundial in the Zhou Dynasty in China.

It was imported into Japan in the Muromachi period, and the kanji form was changed to 時計 in the Edo period.

時計

「時計」は我々の生活に欠かせないものです。

「時計」を構成する漢字は「時」と「計」です。

「時」は "time," 「計」は "measuring" を意味するので、「時計」が "clock/watch" を意味するのはもっともらしく思えるかもしれません。

しかし、「時」という漢字に「と」という読み方は存在しません。

もともと「とけい」は「土圭」と書き、中国周代での緯度測定器や日時計を指す言葉でした。

これが室町時代に日本に伝わり、江戸時代に「時計」という漢字が当てられたというわけです。

• A tokei (時計 - clock/watch) is very important to our lives.
• A tokei (時計 - clock/watch) are is very important to our lives.

  You're not talking about just one watch/clock. You are talking about all of them, generally.

I didn't know this. My wife is Japanese. I'm going to ask her if she knows. Great writing.
-Adam

Great lesson!