Found 2 items, similar to swim bladder.
English → English (WordNet) Definition: swim bladder swim bladder n : an air-filled sac near the spinal column in many fishes that helps maintain buoyancy [syn: air bladder]
English → English (gcide) Definition: Swim bladder Swim \Swim\, n. 1. The act of swimming; a gliding motion, like that of one swimming. --B. Jonson. [1913 Webster] 2. The sound, or air bladder, of a fish. [1913 Webster] 3. A part of a stream much frequented by fish. [Eng.] [1913 Webster] Swim bladder, an air bladder of a fish. To be in the swim, to be in a favored position; to be associated with others in active affairs. [Colloq.] [1913 Webster]