air sacs Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition plural noun. small, thin-walled structures in animals or plants that hold air. Example Sentence Birds ventilate their lungs by means of air sacs. More Example Sentences Air sacs help in gas exchange. Synonyms alveoli; air pockets; lungs Antonyms toe Hear It! Say It! Write It! air sacs Switch to cursive Start Share with your friends:
