can ‧ is ‧ ter /ˈkænəstə, ˈkænɪstə $ -ər/ BrE AmE noun [countable]
[ Date: 1400-1500 ; Language: Latin ; Origin: canistrum 'basket' , from Greek kanastron , from kanna ; ⇨ ↑ cane 1 ]
1 . a round metal case that contains gas and bursts when it is thrown or fired from a gun:
Police fired tear gas canisters into the crowd.
2 . a metal container for keeping something in:
a tea canister
a petrol canister