Osiris is a tiny lunar crater in the southeastern part of the Mare Serenitatis. To the east-northeast of this position is the landing site of the Apollo 17 mission, in the Taurus–Littrow valley. This area of the surface is notable for an interrupted crater chain running from west-southwest to east-northeast. (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.