The Collaborative International Dictionary of English v.0.48:

Mile \Mile\ (m[imac]l), n. [AS. m[imac]l, fr. L. millia, milia;
   pl. of mille a thousand, i. e., milia passuum a thousand
   paces. Cf. Mill the tenth of a cent, Million.]
   A certain measure of distance, being equivalent in England
   and the United States to 320 poles or rods, or 5,280 feet.
   [1913 Webster]

   Note: The distance called a mile varies greatly in different
         countries. Its length in yards is, in Norway, 12,182;
         in Brunswick, 11,816; in Sweden, 11,660; in Hungary,
         9,139; in Switzerland, 8,548; in Austria, 8,297; in
         Prussia, 8,238; in Poland, 8,100; in Italy, 2,025; in
         England and the United States, 1,760; in Spain, 1,552;
         in the Netherlands, 1,094.
         [1913 Webster]

   Geographical mile or Nautical mile, one sixtieth of a
      degree of a great circle of the earth, or 6080.27 feet.

   Mile run. Same as Train mile. See under Train.

   Roman mile, a thousand paces, equal to 1,614 yards English
      measure.

   Statute mile, a mile conforming to statute, that is, in
      England and the United States, a mile of 5,280 feet, as
      distinguished from any other mile.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Nautical \Nau"tic*al\, a. [L. nauticus, Gr. naytiko`s, fr.
   nay`ths a seaman, sailor, fr. nay^s ship: cf. F. nautique.
   See Nave of a church.]
   Of or pertaining to seamen, to the art of navigation, or to
   ships; as, nautical skill.
   [1913 Webster]

   Syn: Naval; marine; maritime. See Naval.
        [1913 Webster]

   Nautical almanac. See under Almanac.

   Nautical distance, the length in nautical miles of the
      rhumb line joining any two places on the earth's surface.


   nautical mile. See under Mile.
      [1913 Webster]

WordNet (r) 3.0 (2006):

nautical mile
    n 1: a former British unit of length equivalent to 6,080 feet
         (1,853.184 meters); 800 feet longer than a statute mile
         [syn: nautical mile, naut mi, mile, mi,
         geographical mile, Admiralty mile]
    2: a unit of length used in navigation; exactly 1,852 meters;
       historically based on the distance spanned by one minute of
       arc in latitude [syn: nautical mile, mile, mi, naut
       mi, knot, international nautical mile, air mile]