Definition of keen :
1. A prolonged wail for a deceased person. Cf. Coranach.
2. Acute of mind; sharp; penetrating; having or expressing mental acuteness; as, a man of keen understanding; a keen look; keen features.
3. Bitter; piercing; acrimonious; cutting; stinging; severe; as, keen satire or sarcasm.
4. Eager; vehement; fierce; as, a keen appetite.
5. Piercing; penetrating; cutting; sharp; - applied to cold, wind, etc, ; as, a keen wind; the cold is very keen.
6. Sharp; having a fine edge or point; as, a keen razor, or a razor with a keen edge.
7. To sharpen; to make cold.
8. To wail as a keener does.
noble, supernal, neat, radical, top-flight, exceptional, furious, astute, fabulous, superior, gone, shrill, in need of something, gale-force, nuts, A-OK, subtle, probing, antsy, prime, profound, hopped-up, prizewinning, juiced, first-string, fine, in the hope that/of, down, smart, discerning, impatient, dreamy, bright, discriminating, bewail, fierce, sharpened, assail, ripping, swell, blue-chip, capital, peachy, brag, kinaesthetic, blue-ribbon, smarting, geeked, corking, phat, good, crazy, top, intelligent, meditative, hard, unsurpassed, gilt-edged, quality, easterly, first-class, hungry, interested, ghastly, fab, voracious, anxious, double-edged, tip-top, urgent, vehement, par excellence, bemoan, gangbusters, brave, fearful, prize, dire, ardent, pumped, athirst, greedy, clear-sighted, bitter, click, choice, dynamite, awesome, frightful, mad, grand, immense, shrewd, primo, number one, fantastical, superlative, dope, stinging, awful, glorious, boffo, penetrative, east, ground, mean, lament, stellar, biting, lovely, whetted, bumper, careful, avid, cracking, fearsome, mewl, serious, groovy, crackerjack, nifty, judicious, fervent, sound, perceive, force, terrible, bang-up, the Beaufort scale, grave, honed, concern, reasoned, piercing, gung ho, lancinate, serrated, ultrasmart, heavy, edged, superb, edgy, hepped up, bursting, dainty, penetrating, sense, warm, recherche, divine, not bad, vicious, distinguish, blistering, wounding, righteous, extreme, marvelous, sensation, explosive, knowing, heavenly, topping, intent, sharp-witted, brainy, fast, gentle, smashing, following, alert, brilliant, wizard, famous, almighty, strong, wild, slick, gusty, needlelike, tremendous, frontline, sterling, terrific, numero uno, be dying for something/to do something, intellectual, top-notch, incisive, high-class, jim-dandy, deductive, enthused, great, nimble, stropped, bully, splendid, creak, supersmart, acuate, two-edged, trenchant, precipitous, quick-witted, excruciating, lancinating, left-handed, out-of-sight, first-rate, wonderful, knifelike, desperate, hyperintelligent, super, deep, agog, solicitous, intensive, stoked, peachy keen, classic, excited, beautiful, thirsting, bonny, insightful, perception, top-shelf, deplore, thirsty, clink, hype, top-of-the-line, cunning, razor-sharp, sagacious, perceptive, sharp-worded, A1, longing, perspicacious, delicate, bleep, dandy, zealous, five-star, slap-up, heavy-duty, fantastic, subtile, enthusiastic, peep, chime, beep, ferocious, fantabulous, raring, assault, desirous, violent, exquisite, thoughtful, dreadful, sensitive, hot, dull, clever, rabid, crafty, sensational, chink, stabbing, quick, boss, four-star, banner, hellacious, ability
enthusiastic (part of speech: adjective)
severe (part of speech: adjective)
demanding, rigid, austere, fundamental, gruff, rigorous, brusque, dry, uncompromising, precise, curt, piquant, correct, brisk, chilly, obstinate, icy, stiff-necked, bleak, obdurate, disciplined, cutting, spare, stringent, hidebound, blunt, caustic, censorious, lean, cool, tart, exacting, basic, acute, sharp, ascetic, acerbic, imperial, raw, astringent, prudish, meticulous, severe, frosty, Spartan, Draconian, harsh, acrimonious, unbending, intense, puritanical, oppressive, intolerant, critical, authoritarian, short, abrupt, strict, stern, relentless, stark, inflexible, crisp, grim, strait-laced, dour
sharp (part of speech: adjective)
sensitive (part of speech: adjective)
- For three days we thought he would live- he was keen to get home; but by the time Craig came we had given up hope. - "Black Rock", Ralph Connor.
- She's taken a fancy to you, and if you're keen as I think you are, you'll call on her without much delay. - "The Eagle's Heart", Hamlin Garland.
- Her keen eyes looked me up and down. - "The Home and the World", Rabindranath Tagore.