Waterman is a lunar crater that is located , and cannot be viewed directly from the Earth. It lies along the southern outer ramparts of the prominent crater Tsiolkovskiy. Almost attached to the southwest is Neujmin, so that Waterman lies straddled between these two features. The outer rim has been somewhat modified by its proximity to Tsiolkovskiy to the north, and it now has a slightly oval shape. (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.