An internal-combustion engine in which an explosive mixture is drawn into the cylinder on the first stroke and is compressed and ignited on the second stroke; work is done on the third stroke and the products of combustion are exhausted on the fourth stroke.

synoniem: four-stroke engine.

Nederlands: viertaktmotor
Pools: czterosuw, czterotakt, silnik czterosuwowy, silnik czterotaktowy