adjective.moderately cold: lacking in warmth

• The plant grows best in cool climates.
• a cool and calculating businessperson

adjective.marked by steady dispassionate calmness and self-control

• They stayed cool through the emergency.
• It's important to keep a cool head =remain calm in a crisis.

adjective.lacking ardor or friendliness

• a cool impersonal manner
• We used to fight, but we're cool now.

verb.to become cool: lose heat or warmth —sometimes used with off or down

• placed the pie in the window to cool
• His anger cooled.

verb.to lose ardor or passion

• cooled the room with a fan
• cooled her growing anger

verb.to make cool: impart a feeling of coolness to —often used with off or down

noun.a cool time, place, or situation

• the cool of the evening
• … his ardor, her cool, his earthiness, her spirituality.

noun.absence of excitement or emotional involvement: detachment

• The player lost his cool and began yelling at the referee.

noun.poise, composure

adverb.in a casual and nonchalant manner

• play it cool