Definitions

1. noun

a tube or airway through which air passes into the lungs; one of the paired air tubes that conduct air into the lungs in insects and other invertebrates

“The tracheae in the grasshopper’s body allowed it to breathe efficiently.”

2. noun

a single trachea

“In some species of insects, there is only one trachea.”

3. plural noun

airways or tubes that transport air in the lungs

“The tracheae of the human body are protected by the bronchi.”