—adj.
1 of or at a fairly low temperature, fairly cold (a cool day; a cool bath).
2 suggesting or achieving coolness (cool colours; cool clothes).
3 calm, unexcited.
4 lacking zeal or enthusiasm.
5 unfriendly; lacking cordiality (got a cool reception).
6 (of jazz playing) restrained, relaxed.
7 calmly audacious (a cool customer).
8 (prec. by a) colloq. at least; not less than (cost me a cool thousand).
9 sl. esp. US excellent, marvellous.
—n.
1 coolness.
2 cool air; a cool place.
3 sl. calmness, composure (keep one's cool; lose one's cool).
—v.tr. & intr. (often foll. by down, off) make or become cool.
Phrases and idioms:
cool-bag (or -box) an insulated container for keeping food cool. cool-headed not easily excited. cool one's heels see HEEL(1). cooling-off period an interval to allow for a change of mind before commitment to action. cooling tower a tall structure for cooling hot water before reuse, esp. in industry. cool it sl. relax, calm down.
Derivatives:
coolish adj. coolly adv. coolness n.
Etymology: OE col, colian, f. Gmc: cf. COLD
Useful english dictionary. 2012.