a measure of length used in the national nonmetric systems of units; now used mainly in navigation.
The USSR and most other countries use the nautical mile, which, according to the International Hydrographic Conference of 1929, is equal to 1.852 km, or the average length of 1’ of the arc of a meridian. One nautical mile is equal to 10 cable lengths.
In Great Britain 1 nautical mile equals 1.853184 km, and 1 statute land mile equals 1.609344 km (it is also used in the USA). A geographic mile (German) is equal to 1/15° of the equator, or 7.4204 km. The old Russian mile was equal to 7.46760 km; the old Roman mile, to 1.481 km.