The Collaborative International Dictionary of English v.0.48:

Neat \Neat\, a. [Compar. Neater; superl. Neatest.] [OE.
   nett, F. nett, fr. L. nitidus, fr. nitere to shine. Cf.
   Nitid, Net, a., Natty.]
   1. Free from that which soils, defiles, or disorders; clean;
      cleanly; tidy.
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            If you were to see her, you would wonder what poor
            body it was that was so surprisingly neat and clean.
                                                  --Law.
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   2. Free from what is unbecoming, inappropriate, or tawdry;
      simple and becoming; pleasing with simplicity; tasteful;
      chaste; as, a neat style; a neat dress.
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   3. Free from admixture or adulteration; good of its kind; as,
      neat brandy; to drink one's vodka neat. Hence: (Chem.)
      Pure; undiluted; as, dissolved in neat acetone. "Our old
      wine neat." --Chapman.
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   4. Excellent in character, skill, or performance, etc.; nice;
      finished; adroit; as, a neat design; a neat thief.
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   5. With all deductions or allowances made; net.

   Note: [In this sense usually written net. See Net, a.,
         3.]
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   neat line (Civil Engin.), a line to which work is to be
      built or formed.

   Neat work, work built or formed to neat lines.
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   Syn: Nice; pure; cleanly; tidy; trim; spruce.
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