1) Butene 2) Hydrocarbon in gasoline 1) Butene 2) Isobutylene 3) Polybutene 4) Polybutylene 
• (n.) Any one of three metameric hydrocarbons, C4H8, of the ethylene series. They are gaseous or easily liquefiable.
Bu'ty·lene noun [ From Butyl .] (Chemistry) Any one of three metameric hydrocarbons, C 4 H 8 , of the ethylene series. They are gaseous or easily liquefiable. 
[n] - any of three isomeric hydrocarbons C4H8
butene noun any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers