When someone has done something which causes you anger and displeasure. You respond by throwing down any item which you are currently holding and yell: "NOT COOL!". Of great importance: the item which has been throw down is now considered community property and may be taken by anyone witnessing said event.
Cool Guy: (walking into a room of friends/coworkers eating burritos) Dude, where's my burrito?
Not Cool Guy: I think they forgot to make it. Or maybe I forgot to order it. (smirks)
Cool Guy: (throwing down container of guacamole -- which he intends those in the room to now eat) NOT COOL!
by not cool guy eating a burrito January 14, 2014
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laid back, relaxed, not freaked out, knows what's goin on.

has come to mean anything popular
"that's one cool cat."

"wow, that good charlotte (cough*sucks*cough) cd is cool!"
by ophelia November 29, 2003
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Showing approval. Something that is favored.
Hey I just got a new ______.
Coolness.
by El Fredo April 11, 2004
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An adjective referring to something that is very good, stylish, or otherwise positive. It is among the most common slang terms used in today's world.
by Ainolketta February 20, 2005
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A word that describes someone or anyone or anything that is interesting and well liked. Cool is over used and often to general and used for things that are often only a fad. The things and people that are in actual fact cool don't care about being cool.
OMG! That dress would look so cool on you!

Dude that deck is freaken cool!
by Stui August 21, 2005
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