What does airline mean?
An airline is a commercial enterprise that transports passengers and freight by air, typically operating scheduled services along defined routes between airports. Airlines range from vast flag carriers with global networks to small regional operators and low-cost carriers that compete primarily on price. The word entered English in the late nineteenth century, borrowed from the notion of an 'air line' — a perfectly straight route — which surveyors and railroad builders had already adopted; when powered flight arrived in the early twentieth century, the term transferred naturally to companies flying such routes. Today 'airline' is a neutral, universally understood term central to discussions of travel, tourism, commerce, and the wider aviation industry. Related expressions include 'flag carrier', denoting a nation's principal airline, and 'budget airline', describing no-frills operators. Because air travel shapes economies and personal mobility alike, the word appears constantly in news, business writing, and everyday conversation.
A company that provides scheduled air transport services for passengers or freight.
"Passengers were rebooked onto another airline after their flight was cancelled."
Also used attributively, as in 'airline food' or 'airline ticket'.
A direct route or straight line through the air; formerly applied to railroads built along the shortest possible path.
"The old air-line railroad prided itself on running the straightest track in the state."
Largely obsolete except in historical accounts and preserved railroad names.
Standard plural; commonly used when discussing the industry collectively, e.g. 'the airlines'.
"Several airlines have reduced fares on transatlantic routes this winter."
The word 'airline' predates passenger aviation itself — early 20th-century writers borrowed it from 'air line', a term railroads used for perfectly straight routes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of airline
The word 'airline' derives from the earlier compound 'air line', meaning a straight, unobstructed route — a sense used by nineteenth-century American railroads, whose 'air-line' routes claimed the shortest possible path between cities. When commercial aviation emerged in the early twentieth century, the term was applied to companies operating aircraft on fixed routes, giving the modern sense. The first element, 'air', comes ultimately from Greek 'aer' via Latin, while the second element reflects the general English pattern of combining a medium of travel with 'line' to denote a route or service, as in 'shipping line'. Cognate formations include other transport compounds built on 'line', such as 'railway line' and 'shipping line'.
How airline is actually used
In everyday usage, 'airline' almost always refers to a transport company. The older geometric sense of 'air line' survives mainly in historical contexts and in the names of some American railroads. The term is neutral in register and used identically in British and American English.
Easily confused with airline
The phrase 'as the crow flies' or 'in a straight line' is sometimes loosely called an 'air line', but this refers to a direct geometric path, not a transport company.