lose one's cool

Not staying cool and in control. The opposite is to keep one's cool.

Don't lose your cool, man!

One will fail if one lose one's cool.

by jimmybone d May 27, 2008

losing one's cool

To lose one's composure. Most people lose their cool when prompted by a negative impetus, like sexual rejection or poor brunch service.

"Losing one's cool is the sexual equivilent of an angry, limp penis."

by Poop.butt. April 11, 2014