Airway
Part of speech: noun
Definition: The trachea. A flight path used by aeroplanes.
Airline
Part of speech: noun
Definition: A company that flies airplanes to transport people and goods.
Example sentence: I have one brother, John, an airline pilot, who is seven years younger. He's adopted, though we're still blood related - he's my cousin. My parents couldn't have any more children after me, so when Dad's brother died, they adopted John, then just a baby.