(zoology) A flexible sac that can expand and contract and that holds liquids or gases.

(anatomy) Specifically, the urinary bladder.

(botany) A hollow, inflatable organ of a plant.

The inflatable bag inside various balls used in sports, such as footballs and rugby balls.

A sealed plastic bag that contains wine and is usually packaged in a cask.

(figurative) Anything inflated, empty, or unsound.

To swell out like a bladder with air; to inflate.

(transitive) To store or put up in bladders.