Wikipedia
A pit-house (or pithouse) is a building that is partly dug into the ground, and covered by a roof. Besides providing shelter from extremes of weather, these structures may also be used to store food and for cultural activities like the telling of stories, dancing, singing and celebrations. General dictionaries also describe a pithouse as a dugout and has similarities to a half-dugout.
In archaeology, pit-houses are frequently termed a sunken featured building (SFB) and occasionally (grub-)hut or grubhouse after the German name Grubenhaus and are found in numerous cultures around the world. These include: the people of the American Southwest, including the ancestral Pueblo, the ancient Fremont and Mogollon cultures, the Cherokee, the Inuit, the people of the Plateau, and archaic residents of Wyoming (Smith 2003) in North America; Archaic residents of the Lake Titicaca Basin (Craig 2005) in South America; Anglo-Saxons in Europe; and the Jōmon people in Japan. Anglo-Saxon pit-houses may have actually represented buildings for other functions than just dwellings.
Usually, all that remains of the ancient pit-house is a dug out hollow in the ground and any postholes used to support the roof. In the nineteenth century, it was believed that most prehistoric peoples lived in pit-houses although it has since been proved that many of the features thought of as houses were in fact food storage pits or served another purpose.