Nautical mile
WordNet
noun
(1) A unit of length used in navigation; equivalent to the distance spanned by one minute of arc in latitude; 1,852 meters
(2) A British unit of length equivalent to 1,853.18 meters (6,082 feet)
WiktionaryText
Noun
By international convention, a unit of measure equal to 1852 meters. Abbreviated as "nm".