Named after Walter Hohmann - German space flight engineer (1880-1945).
Hohmann is a lunar crater that lies within the central basin of the Mare Orientale formation, on the farside. It is located to the south of the crater Maunder, and to the west of Kopff crater. Due to its proximity to the western lunar limb, this area of the surface is occasionally visible during favorable librations. However the basin is viewed from the side, restricting the amount of detail that can be observed from Earth. (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.