noun
tear-gas gun
A firearm-like device that fires tear gas, used for riot control or self-defense.
警察は暴徒を鎮圧するためにガス銃を使用した。
The police used tear-gas guns to suppress the rioters.
noun
gas gun (compressed-air gun)
A gun that uses compressed gas (often CO₂) to propel projectiles; not necessarily a toy.
このガス銃は圧縮空気で弾を発射する。
This gas gun fires projectiles using compressed air.
noun
gas-powered airsoft gun
Commonly called ガスガン; a replica firearm used in airsoft games, powered by gas.
See also: ガスガン
彼はサバイバルゲーム用に新しいガス銃を買った。
He bought a new gas-powered airsoft gun for survival games.