The Collaborative International Dictionary
Air cooling \Air cooling\ In devices generating heat, such as gasoline-engine motor vehicles, the cooling of the device by increasing its radiating surface by means of ribs or radiators, and placing it so that it is exposed to a current of air. Cf. Water cooling. -- Air"-cooled`, a.
Wiktionary
a. Cooled by air (such as an engine, rather than by other means such as water).
WordNet
adj. cooled by a flow of air; "an air-cooled engine"
Usage examples of "air-cooled".
They had to speak loudly to be heard over the air-cooled rotary engine.
It's a multipurpose 4x4 wheeled vehicle with automatic transmission, power steering, and a Detroit Diesel 150-hp diesel V-8, air-cooled engine.
It was a big high-wing monoplane, thick-shouldered, and the single air-cooled radial engine looked enormous.