'airline' originates from the combination of 'air' and 'line', where 'air' refers to the atmosphere and 'line' refers to a route or path.

'airline' was formed in the early 20th century as air travel became more common, combining 'air' with 'line' to denote a route or service.

Initially, it referred to a route for air travel, but it evolved to mean a company providing air travel services.