canister
/ˈkænɪstə(r); `kænɪstɚ/ n
1 small (usu metal) container for holding tea, coffee, etc （通常为金属的）小罐（装茶叶、 咖啡等）.
2 cylinder, filled with shot or tear-gas, that bursts and releases its contents when fired from a gun or thrown 霰弹筒（内装弹丸或催泪气体, 以枪炮发射或投掷後爆炸）.