An Antifreeze

1. A substance, such as glycol, used to lower the freezing point of water;
2. (automobiles) Automotive antifreeze, a solution of ethylene glycol, used as an additive to water or replacement for water, in the radiators of motorcars.
3. (aviation) Deicer, a heated glycol solution used to remove ice from the aerodynamic surfaces of airplanes, and prevent icing while on the tarmac.

The plural form antifreezes is used only if more than one kind of antifreeze is meant.