tetrafluoroethylenePronunciation: /ˌtɛtrəˌflʊərəʊˈɛθɪliːn, -ˌfloː-/Definition of tetrafluoroethylene noun [mass noun] Chemistry a dense colourless gas which is polymerized to make plastics such as polytetrafluoroethylene. Chemical formula: F2CCF2 tetrafluoroethylene in other Oxford dictionaries Definition of tetrafluoroethylene in the US English dictionary