Houtermans is a lunar crater that is located beside the eastern limb , in the region of the surface where visibility is affected by libration. It lies to the east of the crater Kreiken, and south of the crater pairing of Helmert and Kao. This is an elongated formation created by two or more merged crater formations. The crater formation is twice as wide in longitude as it is in latitude, with the long axis oriented toward the west-northwest. (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.