air sac
| 1. |
(noun) any of the membranous air-filled extensions of the lungs of birds |
|
Related Words: sac |
|
| 2. |
(noun) any of the thin-walled extensions of the tracheae of insects |
|
Related Words: sac |
|
| 3. |
(noun) a tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways |
|
Synonyms: air cell, alveolus |
|
Related Words: sac |
|
|