Found 2 items, similar to air bladder.
English → English (WordNet) Definition: air bladder air bladder n : an air-filled sac near the spinal column in many fishes that helps maintain buoyancy [syn: swim bladder]
English → English (gcide) Definition: air bladder air bladder \air" blad`der\ 1. (Anat.) An air sac, sometimes double or variously lobed, in the visceral cavity of many fishes. It originates in the same way as the lungs of air-breathing vertebrates, and in the adult may retain a tubular connection with the pharynx or esophagus. [1913 Webster] 2. A sac or bladder full of air in an animal or plant; also an air hole in a casting. [1913 Webster]