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.).
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            The miller smiled of her nicety.      --Chaucer.
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   2. Delicacy or exactness of perception; minuteness of
      observation or of discrimination; precision.
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   3. A delicate expression, act, mode of treatment,
      distinction, or the like; a minute distinction.
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            The fineness and niceties of words.   --Locke.
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   To a nicety, with great exactness or accuracy.
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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]