\ˈkül \

Definition of cool 

(Entry 1 of 4)

1 : moderately cold : lacking in warmth The plant grows best in cool climates.

2a : marked by steady dispassionate calmness and self-control a cool and calculating businessperson

b : lacking ardor or friendliness a cool impersonal manner

c of jazz : marked by restrained emotion and the frequent use of counterpoint (see counterpoint entry 1)

d : free from tensions or violence We used to fight, but we're cool now.

3 used as an intensive a cool million dollars

4 : marked by deliberate effrontery or lack of due respect or discretion a cool reply

5 : facilitating or suggesting relief from heat a cool dress

6a of a color : producing an impression of being cool specifically : of a hue in the range violet through blue to green

b of a musical tone : relatively lacking in timbre or resonance (see resonance sense 2a)

7 slang

a : very good : excellent That was a really cool movie. also : all right Is getting together Friday night cool with you?

b : fashionable, hip … not happy with the new shoes … because they were not "cool."— Celestine Sibley


cooled; cooling; cools

Definition of cool (Entry 2 of 4)

intransitive verb

1 : to become cool : lose heat or warmth placed the pie in the window to cool sometimes used with off or down

2 : to lose ardor or passion His anger cooled.

transitive verb

1 : to make cool : impart a feeling of coolness to cooled the room with a fan often used with off or down A swim cooled us off a little.

2a : to moderate the heat, excitement, or force of : calm cooled her growing anger

b : to slow or lessen the growth or activity of usually used with off or down wants to cool off the economy without freezing itNewsweek

cool it

: to calm down : go easy The word went out to the young to cool it.— W. M. Young

cool one's heels

: to wait or be kept waiting for a long time especially from or as if from disdain or discourtesy



Definition of cool (Entry 3 of 4)

1 : a cool time, place, or situation the cool of the evening

2a : absence of excitement or emotional involvement : detachment … must surrender his fine cool and enter the closed crazy world of suicide …— Wilfrid Sheed

b : poise, composure The player lost his cool and began yelling at the referee.

3 : hipness



Definition of cool (Entry 4 of 4)

: in a casual and nonchalant manner play it cool

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Other Words from cool


coolish \ˈkü-lish \ adjective
coolly or less commonly cooly \ˈkü(l)-lē \ adverb
coolness \ˈkül-nəs \ noun

Choose the Right Synonym for cool


cool, composed, collected, unruffled, imperturbable, nonchalant mean free from agitation or excitement. cool may imply calmness, deliberateness, or dispassionateness. kept a cool head composed implies freedom from agitation as a result of self-discipline or a sedate disposition. the composed pianist gave a flawless concert collected implies a concentration of mind that eliminates distractions especially in moments of crisis. the nurse stayed calm and collected unruffled suggests apparent serenity and poise in the face of setbacks or in the midst of excitement. harried but unruffled imperturbable implies coolness or assurance even under severe provocation. the speaker remained imperturbable despite the heckling nonchalant stresses an easy coolness of manner or casualness that suggests indifference or unconcern. a nonchalant driver

Examples of cool in a Sentence


The weather is cool today. The surface is cool to the touch. The plant grows best in cool climates. I'm feeling a little cool. We changed into some cooler clothes. She remained calm, cool, and collected.


The fan cools the engine. the cooling effect of the breeze Allow the cake to cool before slicing. the cooling of the ocean waters I took a break from the discussion to allow my anger to cool. His interest in her has cooled somewhat.


the judge's customary cool stood him in good stead during the sensational trial I envy you your cool.


Here comes Mom. Act cool and she won't suspect a thing.
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Recent Examples on the Web: Verb

Here’s a list of cooling centers in Los Angeles County. J. Harry Jones,, "Dangerous Southern California heat wave beginning today is 'one for the record books'," 6 July 2018 Ahead of the anticipated heat wave, municipal officials across the state set up plans for cooling centers for residents., "Brutal Heat Ahead, But Bacteria Could Close Four State Beaches This Weekend," 29 June 2018 But instead of cooling the water, the goal here is to get air in contact with the potassium dissolved in the water, which forsakes its hydroxide partner to grab molecules of CO2. Scott K. Johnson, Ars Technica, "Machines that suck CO₂ from the air might be cheaper than we thought," 7 June 2018 Humans and wildlife require fresh clean water every day for cooling the body and to process and distribute oxygen and nutrients to cells. Kirk Sides, Houston Chronicle, "Birdbaths offer cool dip and sip in summer heat," 5 June 2018 The Legislature followed up by passing rules requiring backup power for cooling for at least 96 hours at all of the state's 685 nursing homes and 3,101 assisted living facilities. Elizabeth Koh, miamiherald, "Could nursing home horror of Hurricane Irma happen again? Most facilities not ready.," 1 June 2018 Frustrated Eagle Road commuters will have two new options for cooling their heels until the traffic abates. Maria L. La Ganga, idahostatesman, "More movie theaters. Cushy reclining seats. Eagle Road will go further upscale.," 30 May 2018 For many years, firefighters thought that air flow had a cooling effect in a building fire, and the more air flowing, the better. Mike Hendricks, kansascity, "In a tragic loop, firefighters continue to die from preventable mistakes," 13 July 2018 Rides were temporarily shut down Thursday evening because of problems with the cooling system. Gabrielle Russon,, "Disney: Rides at Hollywood Studios working again," 13 July 2018

Recent Examples on the Web: Noun

Consumer reporter Steve Noviello has tips on how to keep cool without wasting energy and money. Leah Napoliello, Houston Chronicle, "BBB on Homes: Set your sights on summertime energy savings," 8 July 2018 On a day that saw temperatures soar into the 90s, a Boston police sergeant made sure a black labrador retriever named Olive kept cool. Danny Mcdonald,, "On a sweltering day, a Boston cop made sure a black lab kept cool," 5 July 2018 There’s a lawn in front of us so people can lay down in the cool of the evening. Bradley J. Fikes,, "Fun, patriotism mark final day of San Diego County Fair," 4 July 2018 Once the shoulder has reached 200 degrees, shut off the oven and let the roast cool for a couple of hours before removing from the oven. Lauren Delgado,, "Ghost Scream’s recipe for Spicy Pulled Pork Mini Sliders," 3 July 2018 One guy kept his cool as the star entered the room with a beautiful plant in hand and started singing even harder. Billboard, "Watch Ariana Grande & Jimmy Fallon Surprise Unsuspecting Fans In Heartwarming 'Tonight Show' Sketch," 18 May 2018 Happily, the cop involved kept his cool, and control of his vehicle. Bill Laitner, Detroit Free Press, "Ominous winter freeway threat on I-696 in Southfield: Flying concrete," 31 Jan. 2018 So yes, Mickelson can be understood for losing his cool, for losing his composure, for losing his mind in that moment of frustration, a 10 on the scorecoard en route to a third-round 81. Tara Sullivan,, "Phil Mickelson’s explanation was more ridiculous than his rule breach," 16 June 2018 The day was bright, crisp, a little cool, and his step was brisk. Jon Caramanica, New York Times, "Into the Wild With Kanye West," 25 June 2018

Recent Examples on the Web: Adverb

Let cool slightly, then transfer oil and spice mixture to a bowl. Jonah Miller, WSJ, "Throw a Summer Party the Effortless Spanish Way," 6 July 2018 Let cool completely, cover with plastic or store airtight, and store at room temperature. Claire Saffitz, Bon Appetit, "The 10 Baking Questions People Ask Me Literally All the Time, Answered," 21 May 2018 Let cool completely before storing in the refrigerator for up to 3 weeks. Chris Ross,, "New book is collection of low-alcohol drinks," 4 June 2018 New grass needs to be well established before temperatures start to turn cool in late September. Neil Sperry, star-telegram, "Here’s your gardening to-do list for the second part of the summer," 11 July 2018 Let cool completely before cutting into wedges and serving. San Antonio Express-News, "Recipe: Peach Crostata with Almond Cream," 30 May 2018 When the corn is cool, cut the kernels off the cob, cutting close to the cob. San Antonio Express-News, "Recipe: Sweet Corn Salad," 9 May 2018 Let cool, stirring occasionally to stop a skin from forming, until the glaze is just cool enough to touch (about 10-12 minutes). Bailey Loosemore, The Courier-Journal, "2017 Kentucky State Fair blue ribbon cake recipe – 'Bourbon Cream Tipsy Cake'," 15 Aug. 2017 With pastel-colored shirts, swimsuits, dresses, shorts and more, all featuring fun prints like bananas or candy, this collection will keep your child cool all summer long. Collier Sutter,, "Wear Your Appetite on Your Sleeve with This Food-Inspired Apparel," 25 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cool.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of cool


before the 12th century, in the meaning defined at sense 1


before the 12th century, in the meaning defined at intransitive sense 1


15th century, in the meaning defined at sense 1


1968, in the meaning defined above

History and Etymology for cool


Middle English col, going back to Old English cōl, going back to West Germanic *kōlu- (whence also Middle Dutch coele "moderately cold" and, from a variant *kōlja-, Old High German kuoli), lengthened-grade derivative from the base of *kalan- "to be cold" — more at cold entry 1


Middle English colen, going back to Old English cōlian, verbal derivative from Germanic *kōl- cool entry 1 (whence also Old Saxon colon "to become cool," Old High German kuolēn)


Middle English cole, derivative of col cool entry 1


derivative of cool entry 1

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Learn More about cool

Dictionary Entries near cool

cook up


cook wrasse





Statistics for cool

Look-up Popularity

Time Traveler for cool

The first known use of cool was before the 12th century

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More Definitions for cool



English Language Learners Definition of cool

 (Entry 1 of 3)

: somewhat cold : not warm or hot

: made of a light, thin material that helps you stay cool

: able to think and act in a calm way : not affected by strong feelings



English Language Learners Definition of cool (Entry 2 of 3)

: to make (someone or something) cool

: to become cool : to lose heat or warmth

: to become less strong or intense especially in emotion



English Language Learners Definition of cool (Entry 3 of 3)

: in a calm manner : in a way that does not seem unusual or excited


\ˈkül \
cooler; coolest

Kids Definition of cool

 (Entry 1 of 3)

1 : somewhat cold : not warm a cool day a cool room

2 : not letting or keeping in heat cool clothes

3 : calm entry 3 sense 2 She is cool in a crisis.

4 : not interested or friendly: He was cool to my idea.

5 : fashionable, stylish, or attractive in a way that is widely approved of

6 : very good excellent

Other Words from cool

coolly adverb
coolness noun


cooled; cooling

Kids Definition of cool (Entry 2 of 3)

: to make or become less warm



Kids Definition of cool (Entry 3 of 3)

1 : a time or place that is not warm the cool of the evening

2 : a calm state of mind Keep your cool.

Legal Definition of cool 

: to lose passion : become calm sometimes used with off or down the time elapsing…is such that a reasonable man thus provoked would have cooled— W. R. LaFave and A. W. Scott, Jr.

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Comments on cool

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not any or not one

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