compressed air

air compressed, especially by mechanical means, to a pressure higher than the surrounding atmospheric pressure.

Origin of compressed air

First recorded in 1660–70

The hoisting was done by a small Lidgerwood compressed-air hoister, and set up on an overhead platform across the tunnel.

Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910 |B. H. M. Hewett
In such places, low, compressed-air locomotives were sometimes used; but these were very expensive.

Every-day Science: Volume VI. The Conquest of Nature |Henry Smith Williams
Her motive power consisted of compressed-air engines of eighty horsepower.

The Submarine in War and Peace |Simon Lake
Our compressed-air reservoir was a soda-water fountain tank.

The Submarine in War and Peace |Simon Lake

Prior to 1893 Mr. Hargraves (of cellular kite fame) studied the question of compressed-air motors for model flying machines.

The Theory and Practice of Model Aeroplaning |V. E. Johnson

compressed air

air at a higher pressure than atmospheric pressure: used esp as a source of power for machines