Beijerinck is a lunar crater on the far side. It lies to the south of the larger crater Chaplygin, and to the northeast of the huge walled plain Gagarin. The outer rim of this crater is heavily worn and eroded by subsequent meteor bombardment, particularly along the southern half, with several small and tiny craterlets lying along the rim. The interior floor, in contrast, is level and unmarked by notable impacts. (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.