two-stroke 
adjective
1Denoting an internal combustion engine having its power cycle completed in one up-and-down movement of the piston.According to the EPA, two-stroke engines - which power a variety of other watercraft as well - are a leading source of toxic water pollution....
- Mowers powered by two-stroke engines, for which gasoline and oil are mixed prior to ignition, are dirtiest.
- See also the articles on Hemi engines, rotary engines and two-stroke engines.
1.1Denoting a vehicle having a two-stroke engine.You're referring here to two-stroke vehicles and we haven't ourselves done very many trials on these but we are very hopeful....
- The race was split into four categories 50 cc, four-stroke motorcycles up to 180 cc, novice riders on two-stroke bikes and 100 to 135 cc for the experienced.
- Two-wheeler maker TVS Motor Company has said it plans to replace two-stroke motorcycle ‘Max’ with a four-stroke entry-level motorcycle within six months to arrest the erosion in sales.
noun
A two-stroke engine or vehicle.Four-stroke engines are heavier than two-strokes but the technology means they burn fuel more completely and emit fewer pollutants....
- He and his team created the Evinrude E-TEC family of two-strokes; engines that are clean and darn-near worry free.
- I had some good performances on 500 cc two-strokes in 1998 and 1999 but some still weren't convinced that I could win on the big bikes.