- Aeronautics.
- a system furnishing air transport, usually scheduled, between specified points.
- the airplanes, airports, etc., of such a system.
- a company that owns or operates such a system.
- a direct line; beeline.
- an airhose used to pipe air to a deep-sea diver, pneumatic drill, etc.
- of or on an airline.
- straight; direct; traveling a direct route: Some railroads advertise air-line routes between stations.
- a system or organization that provides scheduled flights for passengers or cargo
- (as modifier)
- a hose or tube carrying air under pressure
- a beeline
