- an engine that uses the expansion of heated air to drive a piston
- a small engine that uses compressed air to drive a piston
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Examples from the Web for air engine
Myself, I do not think He keeps the world waitin' for this air-engine.
Air-engine, an engine in which air heated, and so expanded, or compressed air is used as the motive power.
An air-engine works through the expansion of air in a cylinder by heat.Steam Steel and Electricity
James W. Steele