ALL meanings of air sac
A·ïr sac
A a - noun air sac any of the membranous air-filled extensions of the lungs of birds, which increase the efficiency of gaseous exchange in the lungs 3
- noun air sac any of the thin-walled extensions of the tracheae of insects having a similar function 3
- noun air sac any of the air-filled cavities in a bird's body, having connections to the lungs 3
- noun air sac a saclike dilation of the wall of a trachea in many insects. 1
- noun air sac a sac containing air. 1
- noun air sac alveolus (def 2). 1
- noun air sac any of certain cavities in a bird's body connected with the lungs. 1