Added 10 October 2026 ethylene /ˈɛθɪˌliːn/ noun Categories: NatureUncommon Words noun ! Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about ethylene at Wordnik → Where our words come from → The common name for the organic chemical compound ethene. The simplest alkene, a colorless gaseous (at room temperature and pressure) hydrocarbon with the chemical formula C2H4. The divalent radical derived from ethane. Related Words: ethenepropylenebutylenetetrafluoroethylenestyrenediamineglycoloxidecrtelaylalpha-olefin Back to today's word