noun (n)

• a former British unit of length equivalent to 6,080 feet (1,853.184 meters); 800 feet longer than a statute mile(noun.quantity)

  Synonym:
  admiralty mile, geographical mile, mi, mile, naut mi
  

  source: wordnet30
• a unit of length used in navigation; exactly 1,852 meters; historically based on the distance spanned by one minute of arc in latitude(noun.quantity)

  Synonym:
  air mile, international nautical mile, knot, mi, mile, naut mi
  

  source: wordnet30