[air sac] n (ca. 1828) 1: one of the air-filled spaces in the body of a bird connected with the air passages of the lungs
2: alveolus 1b
3: a thin-walled dilation of a trachea occurring in many insects
[air sac] n (ca. 1828) 1: one of the air-filled spaces in the body of a bird connected with the air passages of the lungs
2: alveolus 1b
3: a thin-walled dilation of a trachea occurring in many insects
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012