1. [syn: air bladder, swim bladder, float]
The Collaborative International Dictionary of English v.0.48:
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.
2. A sac or bladder full of air in an animal or plant; also
an air hole in a casting.
WordNet (r) 3.0 (2006):
n 1: an air-filled sac near the spinal column in many fishes
that helps maintain buoyancy [syn: air bladder, swim