The Oxford Thesaurus An A-Z Dictionary of Synonyms - keen adj.

1) enthusiastic, avid, zealous, devoted, ardent, fervent, fervid, earnest, impassioned, passionate, intense, active; agog, eager, itching, anxious: They are keen fans of TV soap operas. I was keen to go swimming. 2) sharp, sharpened, razor-sharp, razor-like, knife-edged; trenchant, incisive, cutting, rapier-like, pointed, mordant, acid, vitriolic, acerbic, astringent, biting, acrid, acrimonious, stinging, scorching, caustic, searing, withering, virulent, pungent, sarcastic, sardonic: This axe is very keen, so be careful. With his keen wit, the playwright answered his severest critics. His play is a keen satire on the government. 3) painful, bitter, acute, poignant, fierce, grievous, severe, distressing, distressful, strong, deep, profound, intense, extreme, heartfelt: She felt keen resentment at the way she had been treated. 4) vivid, detailed, specific, unmistaken, unmistakable or unmistakeable, distinct: He has a keen recollection of seeing the suspect on the bus. 5) sharp, acute, sensitive, penetrating, discriminating, fine: The bloodhound has an extremely keen sense of smell. 6) intelligent, sharp, acute, perceptive, perspicacious, percipient, sensitive, discerning, astute, smart, bright, discriminating, discriminative, quick(-witted) , shrewd, clever, canny, cunning, crafty, wise: Philip has a keen understanding of what is required of him. 7) keen on or about. fond of, enamoured of, devoted to, interested in: Alan is almost as keen on Mary as on his stamp collection.