Cool has 17 different meanings across 4 categories:
Noun · Verb · Adjective · Proper Noun
A moderate or refreshing state of cold; moderate temperature of the air between hot and cold; coolness.
"The sea breeze brought a welcome cool to the sweltering afternoon, making it just right for an evening walk along the shore."
In plain English: A cool is a slang term for something that is stylish, impressive, or very good.
"That new jacket is totally cool."
Usage: Use "cool" as a noun to describe a moderately low but comfortable temperature, such as when you say the evening air has a pleasant cool. Do not use it this way to refer to popularity or style, which are expressed with the adjective form.
To lose heat, to get colder.
"After sitting out in the hot sun for hours, I finally stepped into the shade where my skin started to cool down."
In plain English: To cool something means to make it less hot or lower its temperature.
"I need to cool my soup before eating it."
Usage: Use "cool" as a verb when something physically loses heat or temperature drops, such as letting soup cool down before eating it. Do not use this form to describe becoming fashionable or calm, as those meanings require the adjective.
neither warm nor very cold; giving relief from heat
"a cool autumn day"
"a cool room"
"cool summer dresses"
"cool drinks"
"a cool breeze"
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"
inducing the impression of coolness; used especially of greens and blues and violets when referring to color
"cool greens and blues and violets"
"the cool sound of rushing water"
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"
being satisfactory or in satisfactory condition
"an all-right movie"
"the passengers were shaken up but are all right"
"is everything all right?"
"everything's fine"
"things are okay"
"dinner and the movies had been fine"
"another minute I'd have been fine"
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"
Having a slightly low temperature; mildly or pleasantly cold.
"The breeze off the lake left the evening air cool and refreshing."
In plain English: Cool means being calm, relaxed, and easy to get along with without getting upset easily.
"The ice cream was so cool that I could eat it right away."
Usage: Use "cool" to describe something that is refreshing and comfortably cold without being freezing, such as a breeze or a drink taken on a hot day. Avoid using it for objects that are merely chilly or for temperatures that are dangerously low.
Initialism of CLIPS Object-Oriented Language.
"The new manager from the Cool family introduced herself to the team on Monday morning."
A surname.
The word cool comes from the Old English cōl, which originally meant "cold" or "calm." It traveled into Middle English with this same sense of low temperature before acquiring its modern figurative meanings.