naut mi 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}]