Knot
a nautical synonym for the geographical mile. The length of the geographical mile, or knot, or nautical Hence when a ship has gone 1 knot it has gone 1.1515 statute miles, or, what is nearly the same thing, a ship which is running 13 knots an hour is traveling at the same speed as a railway train which is going 15 miles an hour. The name is derived from the knots tied on the appendages of a ship's log line.