an unsaturated, flammable alkene, CHCH:CH, a colorless gas obtained in the refining of petroleum, used in making polypropylene, synthetic glycerol, etc.
Origin:
propyl + -ene
See propylene in American Heritage Dictionary 4
noun
A flammable gas, CH3CH:CH2, derived from petroleum hydrocarbon cracking and used in organic synthesis. Also called propene.