Also,
keep a cool head
;
stay cool
;
be cool
;
(take it cool)
. Remain calm and under control, as in
Keep cool, they'll soon show up
, or
Be cool, the surprise is not spoiled
, or
You have to keep a cool head in these volatile situations
, or
Sit tight, take it cool, they won't bother you again
. All these terms employ
cool
in the sense of “not heated by strong emotion,” a usage dating from the late 1300s or even earlier. The first three expressions are colloquial and date from the second half of the 1800s; both of the last two are slang, and the very last
(take it cool)
is the oldest, first recorded in 1841. Also see