di·chlo·ro·di·flu·o·ro·methane \(|)dī|klōrōˌdī|flu̇(ə)rō+\noun Etymology:dichlor- + difluor- + methane : a nontoxic nonflammable easily liquefiable gas CCl2F2 made from carbon tetrachloride by reaction with antimony trifluoride and used as a refrigerant in refrigerators and air-conditioning units and as a propellant in aerosols