The Collaborative International Dictionary of English v.0.48:
Cool \Cool\, a. [Compar. Cooler; superl. Coolest.] [AS.
c[=o]l; akin to D. koel, G. k["u]hl, OHG. chouli, Dan.
k["o]lig, Sw. kylig, also to AS. calan to be cold, Icel.
kala. See Cold, and cf. Chill.]
1. Moderately cold; between warm and cold; lacking in warmth;
producing or promoting coolness.
Fanned with cool winds. --Milton.
2. Not ardent, warm, fond, or passionate; not hasty;
deliberate; exercising self-control; self-possessed;
dispassionate; indifferent; as, a cool lover; a cool
For a patriot, too cool. --Goldsmith.
3. Not retaining heat; light; as, a cool dress.
4. Manifesting coldness or dislike; chilling; apathetic; as,
a cool manner.
5. Quietly impudent; negligent of propriety in matters of
minor importance, either ignorantly or willfully;
presuming and selfish; audacious; as, cool behavior.
Its cool stare of familiarity was intolerable.
6. Applied facetiously, in a vague sense, to a sum of money,
commonly as if to give emphasis to the largeness of the
He had lost a cool hundred. --Fielding.
Leaving a cool thousand to Mr. Matthew Pocket.
Syn: Calm; dispassionate; self-possessed; composed;
repulsive; frigid; alienated; impudent.