Keenest

adjective

1. Often with a prepositional phrase, or with to and an infinitive: showing a quick and ardent responsiveness or willingness; eager, enthusiastic, interested.

   "I’m keen on computers."

2. Fierce, intense, vehement.

   "This boy has a keen appetite."

3. Having a fine edge or point; sharp.
4. Acute of mind, having or expressing mental acuteness; penetrating, sharp.
5. Acrimonious, bitter, piercing.

   "keen satire or sarcasm"