Thesaurus

Synonyms for Keen include:

acceptable, acute, aggravated, apperceptive, apprehensive, bad, bang-up, best, better, big, blood-and-guts, bully, carnassial, chisel-like, cold, concentrated, consuming, corking, cracking, cutting, dagger-like, dandy, deep, discerning, discriminating, drill-like, edged, exquisite, extreme, fang-like, favorable, favourable, fierce, file-like, fulgurating, good, good enough, goodish, great, groovy, hot, immoderate, incisive, insightful, intemperate, intense, intensified, intensive, keen, knifelike, lancinate, lancinating, main, metal-cutting, neat, nifty, not bad, obedient, observant, observing, overwhelming, peachy, penetrating, penetrative, perceptive, piercing, pointed, profound, quick-sighted, raging, razor-sharp, redeeming, respectable, salt, satisfactory, scratching, screaming, severe, sharp, sharp-eyed, sharp-sighted, sharp-toothed, sharpened, slap-up, smart, smashing, solid, stabbing, strong, subtle, superb, swell, tearing, terrible, terrific, thick, trigger-happy, unabated, understanding, utmost, uttermost, vehement, violent, well behaved, well-behaved, wicked, wild

keen is a ADJ.

keen, lament

keen is a VERB.