There have been a number of explanations as to how the name Foster originated in England. The main line is that Foster is a contracted spelling of Forester, a term which described an official in charge of a forest.In the Middle Ages, the forests and woods were almost always owned or controlled by the lord of the manor.s in England, the name means forester or forest ranger. Forster may also have been an inhabitant of Forst, a town in the Rheinpfalz. For immigrants into America, the name has often been anglicized to Foster.