Orc is from Old English orcneas, which appears in the epic poem Beowulf, and refers to one of the races who are called the offspring of Cain during the initial description of Grendel ("Þanon untydras ealle onwocon,/eotenas ond ylfe, ond orcneas", ll.
About the goblins of The Hobbit, Tolkien wrote: They are not based on direct experience of mine; but owe, I suppose, a good deal to the goblin tradition .. especially as it appears in George MacDonald, except for the soft feet which I never believed in [REF].