Origin of cool

before 1000; Middle English cole, Old English cōl; cognate with Middle Low German kōl, Old High German kuoli (German kuhl). See cold, chill

Related forms

Synonym study

1. See cold. 5. See calm. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for cool off

See also cool out

Derived Forms

Word Origin for cool

Old English cōl; related to Old Norse kōlna, Old High German kuoli; see cold, chill
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Idioms and Phrases with cool off (1 of 2)

cool off


see cool down.


Also, cool down or out. Calm down, become less ardent, angry, or agitated, as in We can't discuss it until you've cooled off. The verb cool alone has been used in this sense since approximately a.d. 1000; off and down were added in the late 1800s, and Davy Crockett's Almanac (1836) had: “Resting a while, just long enough to cool out a little.”


Also, cool out. Kill someone, as in They threatened to cool off his brother. [Slang; first half of 1800s] Also see cool out, def. 2.

Idioms and Phrases with cool off (2 of 2)


In addition to the idioms beginning with cool

  • cool as a cucumber
  • cool down
  • cool it
  • cool off
  • cool one's heels
  • cool out

also see:

  • keep cool
  • keep one's cool
  • play it cool
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.