can‧is‧ter /ˈkænəstə, ˈkænɪstə $ -ər/ noun [countable]
[Date: 1400-1500; Language: Latin; Origin: canistrum 'basket', from Greek kanastron, from kanna; ⇒ cane¹]

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

[TahlilGaran] Dictionary of Contemporary English ▲