Named after James Watt - Scottish inventor (1736-1819).
Watt is a lunar crater that is located in the southeastern part. The northwestern third of the crater rim has been completely overlain by the same-sized Steinheil, leaving much of the interior floor covered with the outer rampart of ejecta from the latter formation. The remainder of the rim is somewhat jagged in appearance, with an inward bulge along the southeast rim and a pair of small outward projections to the northeast. The rim is otherwise sharply defined, with only a minor amount of wear. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.