Definition of "Cool" :

noun: great coolness and composure under strain

"Keep your cool."

noun: the quality of being at a refreshingly low temperature

"The cool of early morning."

verb: loose heat

"The air cooled considerably after the thunderstorm."

verb: lose intensity

"His enthusiasm cooled considerably."

verb: make cool or cooler

adjective: marked by calm self-control (especially in trying circumstances); unemotional

"Play it cool."

adjective: fashionable and attractive at the time; often skilled or socially adept

"He's a cool dude."

adjective: used of a quantity or amount (especially of money) for emphasis

"A cool million bucks."

adjective: being satisfactory or in satisfactory condition

adjective: neither warm nor very cold; giving relief from heat

"A cool autumn day."

adjective: psychologically cool and unenthusiastic; unfriendly or unresponsive or showing dislike

"Relations were cool and polite."

adjective: inducing the impression of coolness; used especially of greens and blues and violets when referring to color

"Cool greens and blues and violets."