knot

A unit of speed measurement equal to one nautical mile per hour. Numerically, it is expressed as 1 kn = 1.852 km/h ≈ 0.5 m/s. The symbol kn is the abbreviation of knot, although it is common to express it as kt. This latter form is not entirely convenient since it coincides with the symbol for kiloton (or kilotonne), which is the SI unit used to measure the explosive power of nuclear bombs (a kiloton is equivalent to the energy released by the explosion of 1000 tons of TNT). The knot is used both in air and maritime navigation and also in Meteorology, to express wind intensity.