A canister is a container, usually made of metal or hard plastic, with a lid that keeps its contents fresh and protected. You might store flour in a canister in your kitchen, keep tea bags in a decorative canister on the counter, or find film canisters (small cylindrical containers that used to hold camera film before digital photography).

Canisters are designed to be practical and durable. Unlike flimsy bags or cardboard boxes, a good canister keeps moisture, air, and pests out. Many families keep matching canisters for sugar, coffee, and rice lined up on their kitchen shelves. Some canisters have airtight seals that preserve food for months.

The word can also refer to specialized containers used for specific purposes. A gas canister might fuel a camping stove, while scuba divers breathe from air canisters strapped to their backs. In science labs, teachers might store chemicals in clearly labeled canisters to keep everyone safe.

The key feature of a canister is that it's sturdy, closable, and meant to protect what's inside, whether that's your grandmother's secret cookie-recipe ingredients or equipment for your next outdoor adventure.