nautical mile
     n 1: a British unit of length equivalent to 1,853.18 meters
          (6,082 feet) [syn: {naut mi}, {mile}, {mi}, {geographical
          mile}, {Admiralty mile}]
     2: a unit of length used in navigation; equivalent to the
        distance spanned by one minute of arc in latitude; 1,852
        meters [syn: {mile}, {mi}, {naut mi}, {knot}, {international
        nautical mile}, {air mile}]
Source: WordNet® 2.0