Pronunciation: (tOO'sī"kul), [key]
noting or pertaining to an internal-combustion engine in which two strokes are required to complete a cycle (two-stroke cycle), one to admit and compress air or an air-fuel mixture and one to ignite fuel, do work, and scavenge the cylinder. Cf. four-cycle.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.