KeenKeen (kēn), a. [Compar. Keener (kēn"ẽr); superl. Keenest.] [OE. kene sharp, bold, AS. cēne bold; akin to D. koen, OHG. kuoni, G. kühn, OSw. kyn, kön, Icel. kænn, for kœnn wise; perh. akin to E. ken, can to be able. √45.]
1. Sharp; having a fine edge or point; as, a keen razor, or a razor with a keen edge.

A bow he bare and arwes [arrows] bright and kene. Chaucer.

That my keen knife see not the wound it makes. Shak.

2. Acute of mind; sharp; penetrating; having or expressing mental acuteness; as, a man of keen understanding; a keen look; keen features.

To make our wits more keen. Shak.

Before the keen inquiry of her thought. Cowper.

3. Bitter; piercing; acrimonious; cutting; stinging; severe; as, keen satire or sarcasm.

Good father cardinal, cry thou amen
To my keen curses. Shak.

4. Piercing; penetrating; cutting; sharp; -- applied to cold, wind, etc.; as, a keen wind; the cold is very keen.

Breasts the keen air, and carols as he goes. Goldsmith.

5. Eager; vehement; fierce; as, a keen appetite. “Of full kene will.” Piers Plowman.

So keen and greedy to confound a man. Shak.

6. Wonderful; delightful; marvelous; as, that would be keen. [slang]

☞ Keen is often used in the composition of words, most of which are of obvious signification; as, keen-edged, keen-eyed, keen-sighted, keen-witted, etc.

Syn. -- Prompt; eager; ardent; sharp; acute; cutting; penetrating; biting; severe; sarcastic; satirical; piercing; shrewd.

KeenKeen, v. t. To sharpen; to make cold. [R.]

Cold winter keens the brightening flood. Thomson.

KeenKeen, n. [Ir. caoine.] A prolonged wail for a deceased person. Cf. Coranach. [Ireland] Froude.

KeenKeen, v. i. To wail as a keener does. [Ireland]