keen

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.

I’m keen on you.

Fierce, intense, vehement.

This boy has a keen appetite.

[N]euer did I know / A creature that did beare the ſhape of man / So keene and greedy to confound a man.

Having a fine edge or point; sharp.

The tongues of mocking wenches are as keen As is the Razors edge, inuisible: […]

Come thick Night, / And pall thee in the dunneſt ſmoake of Hell, / That my keene Knife ſee not the Wound it makes, / Nor Heauen peepe through the Blanket of the darke, / To cry, hold, hold.

Acute of mind, having or expressing mental acuteness; penetrating, sharp.

For when we rage, aduiſe is often ſeene By blunting vs to make our wits more keene.

So, when remote futurity is brought / Before the keen inquiry of her thought, / A terrible sagacity informs / The poet's heart; […]

Acrimonious, bitter, piercing.

keen satire or sarcasm

O lawfull let it be / That I have roome with Rome to curſe a while, / Good Father Cardinall, cry thou Amen / To my keene curſes; for without my wrong / There is no tongue hath power to curſe him right.

To make cold, to sharpen.

This is the pureſt exerciſe of health, / The kind refreſher of the ſummer-heats; / Nor, when cold Winter keens the brightening flood, / Would I weak-ſhivering linger on the brink.

A prolonged wail for a deceased person.

[S]he went so swiftly that he could only follow her to the door. The large shape of the car swallowed her up; and the car twisted softly around the little drive and away to the London road. Minutes later he heard its Klaxon, just one sharp keen, like the harsh cry of a sea-bird.