Main Entry: eth·yl·ene

Pronunciation: \ˈe-thə-ˌlēn\

Function: noun

Date: circa 1852

1 : a colorless flammable gaseous unsaturated hydrocarbon C₂H₄ that is found in coal gas, can be produced by pyrolysis of petroleum hydrocarbons, and occurs in plants functioning especially as a natural growth regulator that promotes the ripening of fruit
2 : a divalent hydrocarbon group C₂H₄ derived from ethane

— eth·yl·enic \ˌe-thə-ˈlē-nik, -ˈle-nik\ adjective