ethylene
eth.yl.ene \'eth-*-.le-n\ \.eth-*-'le--nik\ \-ni-k(*-)le-\ n 1: a colorless flammable gaseous unsaturated hydrocarbon CH2=CH2I found in coal gas or obtained by pyrolysis of petroleum hydrocarbons 2: a bivalent hydrocarbon radical -CH2CH2- derived from eth ane - eth.yl.enic aj