Keen (?), a. [Compar. Keener (?); superl. Keenest.] [OE. kene sharp, bold, AS.cne bold; akin to D. koen, OHG. kuoni, G. kuhn, OSw. kyn, kon, Icel. kaenn, for koenn 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.
⇒ 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.
© Webster 1913.
Keen, v. t. To sharpen; to make cold. [R.]
Cold winter keens the brightening flood.
Thomson.
© Webster 1913.
Keen, n. [Ir. caoine.] A prolonged wail for a deceased person. Cf. Coranach. [Ireland]
Froude.
© Webster 1913.
Keen, v. i. To wail as a keener does. [Ireland]
© Webster 1913. | 
