English Reference

Word

cool

US/ˈkuɫ/

UK/kˈuːl/

Definitions

01temperature

A1 · Beginner

adj. slightly cold in a way that is usually pleasant.

adj. of a moderately low temperature; refreshing rather than uncomfortably cold.

“The water in the swimming pool was nice and cool on a hot day.”

“The evening air turned cool as soon as the sun dipped below the horizon, prompting the hikers to reach for their jackets.”

Synonyms

Antonyms

02fashionable or impressive

A2 · Elementary Informal

adj. fashionable, attractive, or impressive in a modern way.

adj. denoting something that is fashionable, trendy, or socially impressive. Informal in register.

“That is a really cool jacket; where did you buy it?”

“The startup's new office has a very cool aesthetic, featuring open spaces and modern art installations.”

Synonyms

Antonyms

03calm

B1 · Intermediate

adj. staying calm and not getting angry or upset.

adj. maintaining composure and emotional control, especially under pressure.

“He stayed cool during the exam even though the questions were hard.”

“The pilot remained remarkably cool throughout the emergency landing, giving clear instructions to the cabin crew.”

Antonyms

04acceptable

B1 · Intermediate Informal

adj. used to say that something is okay or that you agree with a plan.

adj. indicating agreement, approval, or that a situation is acceptable. Primarily informal.

“If you want to meet at six instead of five, that is cool with me.”

“The manager was cool with the team taking a longer lunch break after they finished the project ahead of schedule.”

05to lower temperature

A2 · Elementary

v. to become less hot, or to make something less hot.

v. to reduce in temperature; to lose or cause to lose heat.

“Let the soup cool for a few minutes before you eat it.”

“The engineers designed a sophisticated system to cool the server room and prevent the hardware from overheating.”

Synonyms

Antonyms

06to relax

B2 · Upper Intermediate Slang · Informal

v. to spend time relaxing or doing nothing special.

v. to spend time relaxing or socialising without a specific purpose. Slang usage.

“We were just cooling at my house and listening to music.”

“After a stressful week of finals, the students spent the entire Saturday just cooling by the lake.”

Antonyms

07the cool air

B1 · Intermediate Uncountable noun

n. a place or time that is pleasantly cold.

n. a state or place of moderate coldness or refreshing temperature.

“It was a relief to step out of the sun and into the cool of the church.”

“They sat on the porch enjoying the cool of the evening after a particularly humid summer afternoon.”

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Antonyms

08composure

B2 · Upper Intermediate Uncountable noun

n. the ability to stay calm and controlled.

n. the quality of being calm and in control of one's emotions.

“The player lost his cool and started shouting at the referee.”

“Maintaining one's cool during a high-stakes negotiation is often the difference between success and failure.”

Synonyms

Antonyms

Real-World Examples

“The English word ‘cool’ is used around the world, but what exactly is a cool product in marketing terms?”
Cambridge Judge Business School 27 May 2026
“Rihanna exudes ‘delightfully don’t-care’ coolness, according to an expert on cool.”
The Guardian 5 Jul 2025

Etymology

From Middle English cool, from Old English cōl (“cool, cold, tranquil, calm”), from Proto-West Germanic kōl(ī), from Proto-Germanic kōlaz, kōluz (“cool”), from kalaną (“to be cold, to freeze”), Proto-Indo-European *gel- (“to be cold, to freeze”). Cognates Cognate with North Frisian kuul, kölj (“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.

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.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

ADJECTIVE

cool(A1)

Related words

Idioms

Domain

Programming

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.A1 MoversIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.2.0–3.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 1.0–1.50–23TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.120–224
Frequency
Very common
Level
A1 · BeginnerOxford
Updated

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English Reference