coolant

a fluid agent (gas or liquid) that produces cooling; especially one used to cool a system by transferring heat away from one part to another; "he added more coolant to the car's radiator"; "the atomic reactor used a gas coolant"; "lathe operators use an emulsion of oil and water as a coolant for the cutting tool"

Source: WordNet® 3.1, Princeton University — "WordNet Copyright 2011 by Princeton University. All rights reserved." Used under WordNet's license terms. See methodology for full licensing detail. Word validity for game play may differ from any official game dictionary.