cool

adjective

1
marked by calm self-control (especially in trying circumstances); unemotional
play it cool
keep cool
2
fashionable and attractive at the time; often skilled or socially adept
he's a cool dude
that's cool
3
(used of a number or sum) without exaggeration or qualification
a cool million bucks
4
neither warm nor very cold; giving relief from heat
a cool autumn day
a cool room
5
psychologically cool and unenthusiastic; unfriendly or unresponsive or showing dislike
relations were cool and polite
a cool reception
6
(color) inducing the impression of coolness; used especially of greens and blues and violets
cool greens and blues and violets

1
great coolness and composure under strain
keep your cool
2
the quality of being at a refreshingly low temperature
the cool of early morning

Also useful for “cool”:Unscrambler— Turn loose letters into real words