Cool down Definition 1 of 3Pro Tip 1/3Physical Objects Used when referring to physical items that need to reduce in temperature. I'll wait outside until they cool down the lasagna. Pro Tip 2/3Safety First Mentioned in contexts where cooling something prevents harm, like burns. Cool down the metal before handling it. Pro Tip 3/3Temperature Control Can refer to reducing temperature in an environment, like a room. Can we cool down the room with some air conditioning?