ボンベ

ぼんべ
noun
gas cylinder; tank
tool
1. gas cylinder; gas tank; canister
A strong metal container holding gas under pressure, such as an oxygen tank for diving or medicine, or a small gas canister for a portable stove. From German Bombe.
To carry an oxygen tank on one's back.
カセットコンロのボンベが切(き)れた。
The canister for the portable gas stove ran out.
The diver checked how much air was left in the tank before diving into the sea.

From German Bombe. English 'bomb' is a different word in Japanese: 爆弾(ばくだん).

Common collocations