ˈethəˌlēn noun
( -s )
Etymology: International Scientific Vocabulary ethyl + -ene
1. : a colorless flammable gaseous olefin hydrocarbon CH 2 = CH 2 found in coal gas, now usually obtained by pyrolysis of petroleum hydrocarbons, and used chiefly in organic synthesis (as of ethyl alcohol, polyethylene, and styrene), in promoting growth of plants and ripening of fruits, and as an anesthetic
2. : a bivalent hydrocarbon radical −CH 2 CH 2 − derived from ethane by removal of one hydrogen atom attached to each carbon atom or from ethylene by breaking of the double bond