From WordNet (r) 3.0 (2006):
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, keen, knifelike, penetrating,
penetrative, piercing, sharp]
2: intense or sharp; "suffered exquisite pain"; "felt exquisite
pleasure" [syn: exquisite, keen]
3: 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, keen, neat, nifty, not bad(p), peachy,
slap-up, swell, smashing]
4: 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, keen, knifelike,
piercing, stabbing, lancinate, lancinating]
5: having a sharp cutting edge or point; "a keen blade"
n 1: a funeral lament sung with loud wailing
v 1: express grief verbally; "we lamented the death of the
child" [syn: lament, keen]