polycarbonate UK /ˌpɒ.liˈkɑː.bə.neɪt/US /ˌpɑ.liˈkɑɹ.bə.neɪt/ noun1 •Any of a range of polymers of aromatic carbonates.The cloudiness of the windows on the cars, caused by the degradation of the polycarbonate material of which they are made. — 2024 formspolycarbonates