air-cooled 
adjective
(Especially of an engine) cooled by means of a current of air.The Americans were developing larger tanks, with cast-armour hulls and turrets, better guns, and air-cooled diesel engines....
- Sitting almost upright on one of its floats, only the severe damage to the front end, where its 14-cylinder, air-cooled radial engine was partially torn away on impact, betrays the violence that saw this aircraft downed.
- The Navy reasoned that air-cooled radial engines offered added reliability, especially when operating over water.
- discohexaster
- discoid
- discoidal
- discolith
- discolor
- discolorate
- discoloration
- discolored
- discolorisation
- discolorise
- discolorization
- discolorize
- discolorous
- discolour
- discolouration
- discoloured
- discolouredness
- discolourisation
- discolourise
- discolourization
- discolourize
- discolourment
- discomania
- discomaniac
- discombobulate