keen /ˈkin/
 (a.)敏銳的,銳利的,鋒利的;厲害的,激烈的,強烈的;渴望的,熱心的,喜歡的
 Keen a. [Compar. Keener superl. Keenest.]
 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.”
    So keen and greedy to confound a man.   --Shak.
 Note: ☞ 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.
 Keen, v. t. To sharpen; to make cold. [R.]
    Cold winter keens the brightening flood.   --Thomson.
 Keen, n.  A prolonged wail for a deceased person.  Cf. Coranach. [Ireland]
 Keen, v. i. To wail as a keener does. [Ireland]
 ◄ ►
 keen
      adj 1: having or demonstrating ability to recognize or draw fine
             distinctions; "an acute observer of politics and
             politicians"; "incisive comments"; "icy knifelike
             reasoning"; "as sharp and incisive as the stroke of a
             fang"; "penetrating insight"; "frequent penetrative
             observations" [syn: acute, discriminating, incisive,
              knifelike, penetrating, penetrative, piercing,
              sharp]
      2: intense or sharp; "suffered exquisite pain"; "felt exquisite
         pleasure" [syn: exquisite]
      3: very penetrating and clear and sharp in operation; "an
         incisive mind"; "a keen intelligence"; "of sharp and
         active intellect" [syn: incisive, sharp]
      4: very good; "he did a bully job"; "a neat sports car"; "had a
         great time at the party"; "you look simply smashing" [syn:
          bang-up, bully, corking, cracking, dandy, great,
          groovy, neat, nifty, not bad(p), peachy, slap-up,
          swell, smashing]
      5: as physically painful as if caused by a sharp instrument; "a
         cutting wind"; "keen winds"; "knifelike cold"; "piercing
         knifelike pains"; "piercing cold"; "piercing criticism";
         "a stabbing pain"; "lancinating pain" [syn: cutting, knifelike,
          piercing, stabbing, lancinate, lancinating]
      6: having a sharp cutting edge or point; "a keen blade"
      n : a funeral lament sung with loud wailing
      v : express grief verbally; "we lamented the death of the child"
          [syn: lament]