The Collaborative International Dictionary of English v.0.48:

Nicety \Ni"ce*ty\, n.; pl. Niceties. [OE. nicet['e]
   foolishness.]
   1. The quality or state of being nice (in any of the senses
      of that word.).
      [1913 Webster]

            The miller smiled of her nicety.      --Chaucer.
      [1913 Webster]

   2. Delicacy or exactness of perception; minuteness of
      observation or of discrimination; precision.
      [1913 Webster]

   3. A delicate expression, act, mode of treatment,
      distinction, or the like; a minute distinction.
      [1913 Webster]

            The fineness and niceties of words.   --Locke.
      [1913 Webster]

   To a nicety, with great exactness or accuracy.
      [1913 Webster]

WordNet (r) 3.0 (2006):

nicety
    n 1: conformity with some esthetic standard of correctness or
         propriety; "it was performed with justness and beauty"
         [syn: justness, rightness, nicety]
    2: a subtle difference in meaning or opinion or attitude;
       "without understanding the finer nuances you can't enjoy the
       humor"; "don't argue about shades of meaning" [syn: nuance,
       nicety, shade, subtlety, refinement]

Moby Thesaurus II by Grady Ward, 1.0:

120 Moby Thesaurus words for "nicety":
   absoluteness, accuracy, acquired taste, appreciation,
   appreciation of differences, appreciation of excellence,
   appreciativeness, artistic judgment, attention to detail,
   attention to fact, care for truth, choiceness, circumstantiality,
   civilized taste, civilizedness, connoisseurship, conscientiousness,
   correctness, critical niceness, criticality, criticalness,
   cultivated taste, cultivation, culture, daintiness, delicacy,
   delicate distinction, delicateness, detail, differentia,
   differential, discriminating taste, discriminatingness,
   discrimination, discriminativeness, distinction, elegance,
   exactingness, exactitude, exactness, excellence, exquisiteness,
   faithfulness, fastidiousness, faultlessness, feel, feeling,
   fidelity, fine palate, fine point, fineness, finesse, finicality,
   finicalness, finickiness, finickingness, flawlessness, fussiness,
   good taste, grace, gracefulness, gracility, graciosity,
   graciousness, hairline, judiciousness, literalism, literality,
   literalness, making distinctions, margin, mathematical precision,
   meticulousness, minuteness, narrow margin, nice distinction,
   niceness, niceness of distinction, nuance, palate,
   particle of difference, particularity, particularness, perfection,
   point of difference, polish, preciseness, precisianism, precision,
   punctiliousness, punctuality, quality, refined discrimination,
   refined palate, refinement, right, rightness, rigidity, rigidness,
   rigor, rigorousness, scrupulosity, scrupulousness, selectiveness,
   sense, sensibility, sensitivity, severity, shade of difference,
   sophistication, strictness, subtle distinction, subtlety, tact,
   tactfulness, taste, tastefulness, textualism, the letter,
   wide margin