Knocking in spark-ignition engines occurs when the fuel-air mixture spontaneously and violently ignites ahead of the normal flame front.

A unit of speed, equal to one nautical mile (6,076 feet or 1852 meters) per hour. In the days of sail, speed was measured by tossing overboard a log which was secured by a line. Knots were tied into the line at intervals of approximately six feet.

An abrupt change in direction of plating, frames, keel, deck, or other structure of a ship.

A fixed, annular forward extending duct around the propeller. The propeller operates with a small gap between blade tips and the nozzle internal wall, roughly at the narrowest point.

Developed and patented by Ton Kooren, the president of Dutch Towage Company KOTUG, the Rotor Tug represents a new concept in tug design.

The Kyoto Protocol is an international treaty which extends the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits state parties to reduce greenhouse gas emissions, based on the scientific consensus that global warming is occurring and that human-made CO2 emissions are driving it

A kytoon or kite balloon is a tethered aircraft which obtains some of its lift dynamically as a heavier-than-air kite and the rest aerostatically as a lighter-than-air balloon.