Dictionary.net

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"

neither warm or very cold; giving relief from heat; "a cool autumn day"; "a cool room"; "cool summer dresses"; "cool drinks"; "a cool breeze"

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"

(color) inducing the impression of coolness; used especially of greens and blues and violets; "cool greens and blues and violets"

lose intensity; "His enthusiasm cooled considerably"

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"

used of a number or sum and meaning without exaggeration or qualification; "a cool million bucks"

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"

(informal) 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"

(informal; of a number or sum) without exaggeration or qualification; "a cool million bucks"

neither warm or very cold; giving relief from heat; "a cool autumn day"; "a cool room"; "cool summer dresses"; "cool drinks"; "a cool breeze"

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"

(color) inducing the impression of coolness; used especially of greens and blues and violets; "cool greens and blues and violets"

lose intensity; "His enthusiasm cooled considerably"

Moderately cold; between warm and cold; lacking in warmth; producing or promoting coolness.

Not ardent, warm, fond, or passionate; not hasty; deliberate; exercising self-control; self-possessed; dispassionate; indifferent; as, a cool lover; a cool debater.

Not retaining heat; light; as, a cool dress.

Manifesting coldness or dislike; chilling; apathetic; as, a cool manner.

Applied facetiously, in a vague sense, to a sum of money, commonly as if to give emphasis to the largeness of the amount.

A moderate state of cold; coolness; -- said of the temperature of the air between hot and cold; as, the cool of the day; the cool of the morning or evening.

To make cool or cold; to reduce the temperature of; as, ice cools water.

To moderate the heat or excitement of; to allay, as passion of any kind; to calm; to moderate.

To become less hot; to lose heat.

To lose the heat of excitement or passion; to become more moderate.

Slightly cold; calm; deliberate; not admitting heat; as, a cool room; chilling; lacking in cordiality; impudent; not overstated; as, he made a cool thousand.

To make slightly cold.

To become slightly cold.

Coolly.

Coolness.

Coolly.

Slightly cold: free from excitement: calm: not zealous or ardent: indifferent: impudent; also used in speaking of a sum of money, generally a large sum, by way of emphasizing the amount. (Colloq.) "I would pit her for a cool hundred."-Smollett. "A cool four thousand I never discovered from whom Joe derived the conventional temperature of the four thousand pounds, but it appeared to make the sum of money more to him, and he had a manifest relish in insisting on its being cool."-Dickens.

To make cool: to allay or moderate, as heat, excitement, passion, etc.

Coolly.

Coolness.

To make or become cool or cooler.

Moderate in temperature, feeling, or temperament; self - controlled; self - possessed; apathetic; chilling; slighting.

A moderate temperature approaching cold.

Somewhat cold; calm; indifferent; calmly impudent.

Somewhat cold, approaching to cold; not zealous, not fond.

Freedom from heat.