A guyot is a flat-topped seamount. Guyots show evidence of having been above the surface with gradual subsidence through stages from fringed reefed mountain, coral atoll, and finally a flat topped submerged mountain. Guyots are very commonly found in the Pacific Ocean, and are considered to be extinct volcanoes.
Guyot is a lunar crater on the Moon's far side. It is separated from Kostinskiy crater to the northeast by only a few kilometers of rough terrain. To the west-southwest lies Lobachevskiy crater and the to the east-southeast is Ostwald crater.