cool

1. interjection, slang Used to express that something is acceptable or satisfactory. A: "I'll give you a call in the morning." B: "Cool." A: "Do you want to have pizza for dinner tonight?" B: "Yeah, cool." A: "You can come to the mall with us if you want." B: "Oh, cool!"

2. adjective, slang Sophisticated, fashionable, or knowledgeable of the latest trends. I never hung out with any of the so-called "cool kids" in school. I had way more in common with the kids in band and computer club. Ugh, I hate it when my parents try to act all cool. Like, you're not teenagers—stop pretending to be! We dated for a while, but I always felt like she was way too cool for me.

3. adjective, informal Calm, composed, or unflustered. You've got to stay cool when the boss comes in. Don't let him see that anything is wrong! She was so cool when she made the request that I didn't think anything of it at the time. A: "There's a security checkpoint up ahead! What if they search us and find the loot?" B: "Be cool, man! They'll definitely search us you're freaking out."

4. adjective, slang Very exciting or interesting. Hollywood has always made guns seem cool. A: "I just booked a flight to Paris!" B: "Wow, that's so cool! When are you going?" It was pretty cool getting to see New York City from the inside of a helicopter.

5. adjective, slang Not a problem. A: "I'm sorry for what I said earlier." B: "It's cool, man. Don't worry about it." It's cool, I know you would have been here on time if traffic hadn't been such a mess. A: "Sorry I didn't save a seat for you, I just didn't know you were coming to the lecture." B: "It's cool, it was a last-minute decision on my part."

6. adjective, slang Unqualified or unexaggerated. I made a cool two million playing the stock markets last year. Yeah, I could make a cool million for, like, an hour of work, but said work is also illegal! A: "Ladies, guess who just won a cool $50 at the craps table?" B: "Are we supposed to be impressed or something?"

7. noun, informal A calm composure or temper. I tried to keep my cool when the famous actor came into my store. He really lost his cool when the waiter dropped his food. He's a toddler—do you really think he's gonna keep his cool when he has to get a shot at the doctor's office?

cool

1. mod. unabashed; unruffled; relaxed. (see also keep one’s cool, lose one’s cool.) She is totally cool and easygoing.

2. mod. good; excellent. This is a really cool setup!

3. mod. [of music] mellow; smooth. This stuff is so cool, I’m just floating.

4. mod. no less than [some amount of money]. She cleared a cool forty thousand on the Wilson deal.

5. in. to die; to become cold after death. (Medical euphemism.) We were afraid that he would cool.

cooler

n. jail. (Usually with the.) Do you want to talk, or do you want to spend a little time in the cooler?

cool!

Stylish, fashionable, clever. This slangy term expressing admiration dates from the early 1900s as an adjective and was popularized by black jazz musicians from the late 1940s. As an interjection it was then taken up by teenagers and then by the general population. Describing the plan for an assassination, a character in James Patterson’s London Bridges (2004) exclaimed, “Not only is this smart, it is cool as hell.”

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