Definition of keen:
(adj) :
Sharp; having a
fine edge or point; as, a keen razor, or a razor with a keen edge;
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.
(v) :
to sharpen; to make cold. [R.]; to utter a keen
"Cold winter keens the brightening flood." -Thomson.
(n) :
a prolonged
wail for a deceased person