cool

noun
A fairly low temperature. (the cool of the night air)
Calmness; composure. (he recovered his cool and then started laughing at us)
The quality of being fashionably attractive or impressive. (all the cool of high fashion)

verb
Become or cause to become less hot. (we dived into the river to cool off)

adjective
Of or at a fairly low temperature. (it'll be a cool afternoon)
Showing no friendliness toward a person or enthusiasm for an idea or project. (he gave a cool reception to the suggestion for a research center)
Fashionably attractive or impressive.
Used to emphasize a specified quantity or amount, especially of money.