Named after Lewis Boss - American astronomer (1846-1912).
Boss is a lunar impact crater that is located along the northeast rim 's near side. Due to its location, the crater is viewed from the side by observers on the Earth, and its visibility is subject to libration effects. This formation has not been significantly eroded by impacts, and it retains a well-defined outer rim that is not overlain by smaller craters of note. The inner wall is wide and has a terraced surface. (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.