Board Thread:Lore Texts/@comment-34241117-20181113220606/@comment-34030170-20181114140144

"Orc is not an English word. It occurs in one or two places but is usually translated goblin (or hobgoblin for the larger kinds). Orc is the hobbits' form of the name given at that time to these creatures, and it is not connected at all to our orc, ork, applied to sea-animals of dolphin-kind."

-The Hobbit.

I don't see how you could get any clearer than that. If Orcs and Goblins aren't the same thing, than the Orcs and, as the Elves call them, yrch are different, too. It's just a different language.