: moderately cold : lacking in warmth
The plant grows best in cool climates.
: marked by steady dispassionate calmness and self-control
a cool and calculating businessperson
: lacking ardor or friendliness
a cool impersonal manner
: marked by restrained emotion and the frequent use of counterpoint
: free from tensions or violence
We used to fight, but we're cool now.
—used as an intensive a cool million dollars
: marked by deliberate effrontery or lack of due respect or discretion
a cool reply
: facilitating or suggesting relief from heat
a cool dress
of a color
: producing an impression of being cool
: of a hue in the range violet through blue to green
: very good : excellent
That was a really cool movie.
: all right
Is getting together Friday night cool with you?
: fashionable, hip
… not happy with the new shoes … because they were not "cool."— Celestine Sibley
: to become cool : lose heat or warmth
placed the pie in the window to cool
—sometimes used with off or down
: to lose ardor or passion
His anger cooled.
: to make cool : impart a feeling of coolness to
cooled the room with a fan
—often used with off or down A swim cooled us off a little.
: to moderate the heat, excitement, or force of : calm
cooled her growing anger
: to slow or lessen the growth or activity of
—usually used with off or down wants to cool off the economy without freezing it — Newsweek
cool one's heels
: to calm down : go easy
The word went out to the young to cool it.— W. M. Young
: to wait or be kept waiting for a long time especially from or as if from disdain or discourtesy
: a cool time, place, or situation
the cool of the evening
: absence of excitement or emotional involvement : detachment
… must surrender his fine cool and enter the closed crazy world of suicide …— Wilfrid Sheed
: poise, composure
The player lost his cool and began yelling at the referee.
: in a casual and nonchalant manner
play it cool