General English

  • adjective cold in a pleasant way, or colder than you would like or than you expect
  • adjective not friendly or not enthusiastic
  • adjective good
  • noun a colder area which is pleasant
  • noun the state of being calm
  • verb to make something cool; to become cool

General Science

  • verb to make or become less hot


  • verb to become or cause to become less hot


  • verb to reduce the temperature of food by any of a variety of means, e.g. by placing it in a refrigerator, plunging it in cold water or standing its container in cold water


  • noun sang-froid, imperturbability. A back-formation from the adjective.
  • verb to calm down. A more fashionable abbreviated form of the colloquial ‘cool down’, heard since 2000.

Origin & History of “cool”

Cool comes from the same source as cold, namely Indo-European *gel-, *gol- (from which English also gets congeal, gel, and jelly). The Germanic descendants of this Indo-European base were *kal-, *kōl-. From these were derived the Germanic adjective *kōluz, which passed into Old English as cōl. Its use for ‘fashionable, hip’ is mid-20th-century, but its nonchalant application to large sums of money is of surprisingly long standing: ‘I just made a couple of bets with him, took up a cool hundred, and so went to the King’s Arms’, John Vanbrugh and Colly Cibber, The Provok’d Husband 1728.