Noun:
1: cool the quality of being at a refreshingly low temperature; "the cool of early morning"
2: cool, poise, sang-froid, aplomb, assuredness great coolness and composure under strain; "keep your cool"
Verb:
1: cool, cool down, chill make cool or cooler; "Chill the food"
2: chill, cool, cool down loose heat; "The air cooled considerably after the thunderstorm"
3: cool, cool off, cool down lose intensity; "His enthusiasm cooled considerably"
Adjective:
1: precooled, air-conditioned, water-cooled, caller, cool, chilly, air-cooled, chill neither warm nor very cold; giving relief from heat; "a cool autumn day"; "a cool room"; "cool summer dresses"; "cool drinks"; "a cool breeze"
2: nerveless, composed, coolheaded, cool marked by calm self-control (especially in trying circumstances); unemotional; "play it cool"; "keep cool"; "stayed coolheaded in the crisis"; "the most nerveless winner in the history of the tournament"
3: cold, cool (color) inducing the impression of coolness; used especially of greens and blues and violets; "cool greens and blues and violets"
4: unresponsive, cool psychologically cool and unenthusiastic; unfriendly or unresponsive or showing dislike; "relations were cool and polite"; "a cool reception"; "cool to the idea of higher taxes"
5: unqualified, cool (used of a number or sum) without exaggeration or qualification; "a cool million bucks"
6: fashionable, cool, stylish fashionable and attractive at the time; often skilled or socially adept; "he's a cool dude"; "that's cool"; "Mary's dress is really cool"; "it's not cool to arrive at a party too early"