Emily Dickinson Lexicon

KEEN, a. [Sax. cene; G. kühn; D. koen; properly, bold, stout, eager, daring, from shooting forward. Class Gn.]

1. Eager; vehement; as, hungry curs too keen at the sport. – Tatler. The sheep were so keen on the acorns. – L'Estrange.
2. Eager; sharp; as, a keen appetite.
3. Sharp; having a very fine edge; as, a keen razor, or a razor with a keen edge. We say, a keen edge, but a sharp point.
4. Piercing; penetrating; severe; applied to cold or to wind; as, a keen wind; the cold is very keen.
5. Bitter; piercing; acrimonious; as, keen satire or sarcasm. Good father cardinal, cry thou amen, / To my keen curses. – Shak.