Kaminari and Inazuma (雷と稲妻 - Thunder and Lightning)

"Kaminari" (雷) is a natural phenomenon that generates light and sound due to discharge in the air, and is often translated as "thunder."

The etymology of "kaminari" is simple -- it comes from "kami no narasu oto" (神の鳴らす音), the literal meaning of which is "the sound rung by God."

On the other hand, there is another word "inazuma" (稲妻), which has the same meaning of "kaminari," though "inazuma" is often translated into "lightning."

The "ina" (稲) of "inazuma" means "rice," and "zuma/tsuma" (妻) means "husband" here.
(Note that "tsuma" means "wife" now, but once it could mean both "wife" and "husband.")

Thunder/lightning often occurs from summer to autumn, which is when rice grows.

Because of this, it was thought that lightning is a husband of rice (ine/ina no tsuma/zuma), and we have come to call lightning "inazuma."

雷と稲妻

「雷」は、空気中の放電によって光と音を発生する自然現象です。

この言葉の語源はシンプルで、「神が鳴らす音」から来ています。

一方、同じ自然現象を指す言葉に「稲妻」があります。

「稲」は「稲穂」を意味し、「妻」は現在の意味とは異なりここでは「夫」を意味します。

雷は稲穂が実る夏から秋にかけて多く発生します。

このため、雷は稲を実らせることができる「稲の夫（つま）」であると考えられ、稲妻とも呼ばれるようになりました。