noun🔗Share(official IUPAC name) The organic compound acetylene. The simplest alkyne, a colorless gaseous (at room temperature and pressure) hydrocarbon with the chemical formula C2H2."Welding torches often use ethyne as a fuel because it burns with a very hot flame. "compoundsubstancechemistryfueltechnicalscienceChat with AIVocabulary GamePractice Reading