acuity

acuity
    n 1: sharpness of vision; the visual ability to resolve fine
         detail (usually measured by a Snellen chart) [syn:
         {acuity}, {visual acuity}, {sharp-sightedness}]
    2: a quick and penetrating intelligence; "he argued with great
       acuteness"; "I admired the keenness of his mind" [syn:
       {acuteness}, {acuity}, {sharpness}, {keenness}]
    

Acuity \A*cu"i*ty\, n. [LL. acuitas: cf. F. acuit['e].]
   Sharpness or acuteness, as of a needle, wit, etc.
   [1913 Webster]
    

81 Moby Thesaurus words for "acuity":
      acridity, acumen, acumination, acuteness, adroitness, agility,
      alertness, apperception, aptitude, aptness, astuteness, attention,
      attentiveness, braininess, brightness, brilliance, clear thinking,
      cleverness, cogency, dexterity, discernment, edge, esprit,
      farseeingness, farsightedness, flair, foresight, foresightedness,
      genius, giftedness, gifts, incisiveness, insight, keen-wittedness,
      keenness, longheadedness, longsightedness, mental alertness,
      mercurial mind, mucronation, native cleverness, nimble mind,
      nimble-wittedness, nimbleness, nous, penetration, perception,
      perceptiveness, percipience, perspicaciousness, perspicacity,
      perspicuity, perspicuousness, pointedness, prickliness,
      promptitude, promptness, providence, punctuality, quick parts,
      quick thinking, quick wit, quick-wittedness, quickness, readiness,
      ready wit, sagaciousness, sagacity, savvy, sensibility,
      sharp-wittedness, sharpness, sleeplessness, smartness, smarts,
      spinosity, sprightly wit, talent, thorniness, trenchancy,
      wakefulness