a metallic cylinder packed with shot and used as ammunition in a firearm
"The hunter loaded the canister into his shotgun, knowing it would scatter dozens of small pellets to take down the flock at once."
A cylindrical or rectangular container usually of lightweight metal, plastic, or laminated pasteboard used for holding a dry product (as tea, crackers, flour, matches).
"She reached into the pantry and pulled out a large canister to grab some leftover flour for her baking."
To pack into a canister.
"The technician carefully packed the chemical waste into a sealed canister before transporting it to the disposal site."