dichlorodifluoromethane (da??kl??r??da??fl??r???mi??e?n) n (Elements & Compounds) a colourless nonflammable gas easily liquefied by pressure: used as a propellant in aerosols and fire extinguishers and as a refrigerant. Formula: CCl2F2. See also FreonCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014