An airway is a passageway for air. This can be the natural windpipe that takes air from our mouths to our lungs, a breathing tube inserted into someone having difficulty breathing, or a ventilation passage in a mine.
Regardless of which of the above definitions you are considering, remember, getting air to your lungs is recommended by the surgeon general as a really wonderful thing to do pretty much continuously.
An airway can also be a designated flight path for an airplane. A synonym for this sense of the word airway is air lane. I had something to say in that entry about the whole idea of forcing planes to not fly on the straightest path between their departure and arrival points. Feel free to look it up. Or not. It’s entirely your call.