From Middle English cool, from Old English cōl (“cool, cold, tranquil, calm”), from Proto-West Germanic *kōl(ī), from Proto-Germanic *kōluz (“cool”), from *kalaną (“to be cold, to freeze”), Proto-Indo-European *gel- (“to be cold, to freeze”). Cognates Cognate with North Frisian kool, koul, kuul, kölj, kööl (“cold”), Saterland Frisian köil (“cool”), West Frisian koel (“cool”), Cimbrian khuul (“chilly, cool”), Dutch koel (“cool”), German kühl (“cool”), Low German köhl (“cool”), Luxembourgish kill (“cool”), Vilamovian kił (“cool”); also Latin gelū, gelum, gelus (“frost; chill, cold”), Belarusian хо́лад (xólad, “cold”), Bulgarian хлад (hlad, “chill, coolness”), Czech chlad (“cold”), Macedonian лад (lad, “shade; coolness”), Polish chłód (“cold”), Russian and Ukrainian хо́лод (xólod, “cold”), Serbo-Croatian хла̑д, hlȃd (“shade”), Sanskrit जड (jaḍa, “cold; stiff”), जल (jala, “water”). Related to cold.
I like cool weather the most 'cause it's not too hot to wear a jacket but I won't be too cold in my shorts.
The day was cool and snappy for August, and the Rise all green with a lavish nature. Now we plunged into a deep shade with the boughs lacing each other overhead, and crossed dainty, rustic bridges over the cold trout-streams, the boards giving back the clatter of our horses' feet:[…].1897 December (indicated as 1898), Winston Churchill, chapter VIII, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd., →OCLC:
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Many exoplanets have been found orbiting dwarf stars that are much cooler and smaller than our sun, such as the famed TRAPPIST-1 system and its seven planets, announced in 2017.2023 November 29, Ashley Strickland, “Astronomers discover nearby six-planet solar system with ‘pristine configuration’”, in CNN:
2
Allowing or suggesting heat relief.
Linen has made cool and breathable clothing for millennia.
Now that she had rested and had fed from the luncheon tray Mrs. Broome had just removed, she had reverted to her normal gaiety. She looked cool in a grey tailored cotton dress with a terracotta scarf and shoes and her hair a black silk helmet.1963, Margery Allingham, chapter 2, in The China Governess: A Mystery, London: Chatto & Windus, →OCLC:
3
Of a color, in the range of violet to green.
If you have a reddish complexion, you should mainly wear cool colors.
4
Of a person Not showing emotion; calm and in control of oneself.
Its cool stare of familiarity was intolerable.1850, Nathaniel Hawthorne, “Hester at her Needle”, in The Scarlet Letter, a Romance, Boston, Mass.: Ticknor, Reed, and Fields, →OCLC:
In that supposed event, you say, you will destroy the Union; and then, you say, the great crime of having destroyed it will be upon us! That is cool.1860 February 27, Abe Lincoln, Cooper Union address:
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"Well, that's cool," said Laurie to himself, "to have a picnic and never ask me!"1868, Louisa M[ay] Alcott, chapter 13, in Little Women: […], 1st part, Boston, Mass.: Roberts Brothers, published 1869, →OCLC:
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Applied facetiously to a sum of money, commonly as if to give emphasis to the largeness of the amount.
Who will lend me a cool hundred.1749, Henry Fielding, The History of Tom Jones, a Foundling, volume (please specify |volume=I to VI), London: A[ndrew] Millar, […], →OCLC:
But she had wrote out a little coddleshell in her own hand a day or two afore the accident, leaving a cool four thousand to Mr. Matthew Pocket.1860 December – 1861 August, Charles Dickens, chapter XVIII, in Great Expectations […], volume III, London: Chapman and Hall, […], published October 1861, →OCLC, page 303:
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You remember Bulger, don't you? You lost a cool hundred to him one night here over the cards, eh?1900, Dora Sigerson Shorter, Transmigration:
My father was talking to the World's Fair Commission yesterday, and they estimate it's going to cost a cool fifty million.1944 November 28, Irving Brecher, Fred F. Finklehoffe, Meet Me in St. Louis, Metro-Goldwyn-Mayer:
8
Informal, Of a person Knowing what to do and how to behave; behaving with effortless and enviable style and panache; considered popular by others.
[…] while the coachman holding whip and reins in one hand, takes off his hat with the other, and resting it on his knees, pulls out his handkerchief, and wipes his forehead, partly because he has a habit of doing it, and partly because it's as well to shew the passengers how cool he is, and what an easy thing it is to drive four-in-hand, when you have had as much practice as he has.1836 March – 1837 October, Charles Dickens, chapter 28, in The Posthumous Papers of the Pickwick Club, London: Chapman and Hall, […], published 1837, →OCLC, page 284:
Maggie the au pair, and Pam P. on the school bus and Billy G. with his Grateful Dead records were all deeply cool people. But they weren’t cool because they smoked. They smoked because they were cool.2000, Malcolm Gladwell, The Tipping Point:
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He managed to conduct interviews with the least cool global figure – his father, Prince Charles – and the most cool, Barack Obama, in a way that allowed them both to look as good as they could.2017 December 27, “The Guardian view on Prince Harry: the monarchy’s best insurance policy”, in the Guardian:
Is there a secret sauce that helps explain why people as different as David Bowie, Samuel L. Jackson and Charli XCX all seem so self-assured and, well, cool? A new study suggests that there are six specific traits that these people tend to have in common: Cool people are largely perceived to be extroverted, hedonistic, powerful, adventurous, open and autonomous.2025 June 30, Christina Caron, “What Makes Someone Cool? A New Study Offers Clues.”, in The New York Times, New York, N.Y.: The New York Times Company, →ISSN, →OCLC:
You be nice without long hair. Now it's cool, hmm?1953, Dalton Trumbo, Ian McLellan Hunter, John Dighton, Roman Holiday, spoken by Mario Delani (Paolo Carlini):
2008, Lou Schuler, "Foreward", in Nate Green, Built for Show, page xii The fact that I was middle-aged, bald, married, and raising girls instead of chasing them didn't really bother me. Muscles are cool at any age.
Now everything's cool, Drac's a part of the band / And my Monster Mash is the hit of the land / For you, the living, this Mash was meant too / When you get to my door, tell them Boris sent you.1962, “Monster Mash”, Bobby "Boris" Pickett, Lenny Capizzi (lyrics), performed by Bobby (Boris) Pickett and The Crypt-Kickers:
From Middle English cool, from Old English cōl (“cool, cold, tranquil, calm”), from Proto-West Germanic *kōl(ī), from Proto-Germanic *kōluz (“cool”), from *kalaną (“to be cold, to freeze”), Proto-Indo-European *gel- (“to be cold, to freeze”). Cognates Cognate with North Frisian kool, koul, kuul, kölj, kööl (“cold”), Saterland Frisian köil (“cool”), West Frisian koel (“cool”), Cimbrian khuul (“chilly, cool”), Dutch koel (“cool”), German kühl (“cool”), Low German köhl (“cool”), Luxembourgish kill (“cool”), Vilamovian kił (“cool”); also Latin gelū, gelum, gelus (“frost; chill, cold”), Belarusian хо́лад (xólad, “cold”), Bulgarian хлад (hlad, “chill, coolness”), Czech chlad (“cold”), Macedonian лад (lad, “shade; coolness”), Polish chłód (“cold”), Russian and Ukrainian хо́лод (xólod, “cold”), Serbo-Croatian хла̑д, hlȃd (“shade”), Sanskrit जड (jaḍa, “cold; stiff”), जल (jala, “water”). Related to cold.
1
A moderate or refreshing state of cold; moderate temperature of the air between hot and cold; coolness.
in the cool of the morning
2
A calm temperament.
3
The property of being cool, popular or in fashion.
cool
verb
Etymology From Middle English colen, from Old English cōlian (“to cool, grow cold, be cold”), from Proto-West Germanic *kōlēn (“to become cold”), from Proto-Indo-European *gel- (“to freeze”). Cognate with Dutch koelen (“to cool”), German kühlen (“to cool”), Swedish kyla (“to cool, refrigerate”). Also partially from Middle English kelen, from Old English cēlan (“to cool, be cold, become cold”), from Proto-West Germanic *kōlijan, from Proto-Germanic *kōlijaną (“to cool”), altered to resemble the adjective cool. See keel.
Send Lazarus, that he may dip the tip of his finger in water, and cool my tongue.1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, Luke 16:24:
3
Figuratively To become less intense, e.g. less amicable or passionate.
Relations cooled between the USA and the USSR after 1980.
4
Figuratively To make less intense, e.g. less amicable or passionate.
We have reason to cool our raging motions, our carnal stings, our unbitted lusts.c. 1603–1604 (date written), William Shakespeare, “The Tragedie of Othello, the Moore of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act I, scene iii]:
Maybe he would die. That would mean I had murdered him. I smiled, trying the idea on for size. One of the things that always had cheesed me a little was that I had no kills to my credit. I'd been in plenty of rumbles, but somehow, I'd never cooled anyone. Well maybe now I had my first one. I couldn't feel very proud of skulling an old man, but at least I could say that I'd scored. That was a big kick.1965, "Sex Jungle" (narrated in Perversion for Profit)
Big-mouth got up as fast as he could, and I was thinking how much heart he had. But I ran toward him like my life depended on it; I wanted to cool him.1967, Piri Thomas, Down These Mean Streets, New York, N.Y.: Alfred A. Knopf, page 31:
Seen my homeboys coolin' way way out / Told 'em bout my mornin' cold bugged' em out1986, “6 in the Mornin'”performed by Ice-T:
"What up, kid?" ¶ "Coolin'."2000, Paul Beatty, Tuff: A Novel, New York, N.Y.: Anchor Books, published 2001, →ISBN, page 223:
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Asbestos? Raa, dat's a dangerous t'ing boy, dat ain't good. You know what though, you guys should min' yourselves walkin' street star, dere's bere nutters about. I know you're in a crew but boy can't you jus' cool' at someone's house?'1997, Courttia Newland, The Scholar: A West Side Story, London: Abacus, →ISBN, page 207: