Pronunciation: (âr'līn"),[key] —adj. straight; direct; traveling a direct route: Some railroads advertise air-line routes between stations.
Pronunciation: (âr'līn"),[key] —n. 1. Aeron. a. a system furnishing air transport, usually scheduled, between specified points.
b. the airplanes, airports, etc., of such a system.
c. Often, airlines. a company that owns or operates such a system.
2. a direct line; beeline.
3. an airhose used to pipe air to a deep-sea diver, pneumatic drill, etc.