A guyot is an underwater mountain or seamount with a flat top. This geologic feature is also called a tablemount. In general, the guyot or tablemount is over 200 meters (660 feet) below the surface of the sea. The diameters of these flat underwater summits may be more than 10 km (6.2 mi).[1]
↑GuyotEncyclopædia Britannica Online; retrieved 2012-06-09.