(kēn) adjective
1. Very sharp, as a knife.
2. Cutting; piercing, as wit.
3. Vivid; pungent.
4. Having or exhibiting sharpness or penetration; shrewd.
5. Acute: keen sight.
6. Exceptionally intelligent.
7. Characterized by intensity, force, or zest: a keen appetite. See synonyms under ACUTE, ARDENT, ASTUTE, CLEVER, EAGER¹, FINE¹, KNOWING, SAGACIOUS, SHARP, VIVID. [OE cēne]
—keen′ly adverb
—keen′ness noun

(kēn) noun
A wailing cry; dirge.
—v.i. To wail loudly over the dead. [<Irish caoine <caoinim I wail]
—keen′er noun