: : : Ettin (etten) has a similar Anglo-Saxon origin to Ent. But I think here Tolkien was using the word in it's original meaning: ie a man-like creature of giant size. So in this particular case I would imagine the "Ettins" in question were trolls.

: : ::: I agree with the notion that trolls were the basis for the word "Ettenmoors". Remember that Fangorn, boasting of his strength, said that Morgoth had created the trolls in mockery of the Ents, but the Ents were still many times stronger. And also remember the troll incident during the quest for Erebor in the Hobbit? I imagine that trolls had always lived there, but were for a time driven out during the power of Arnor, and then returned after Arnor ceased to exist.

: What about the stone-giants of the Hobbit. If they were trolls, why didn't JRRT say so, since he had just finished dealing with Tom, Bert and the other one whose name I can't recall? Could these stone-giants have been the "Ettins" in question? And if yes, and the Ettenmoors were their original homeland, then why had they moved to the Misty Mountains by the time of the Hobbit? Angmar? Dúnedain hunting parties? Granted, it is highly unlikely that they were another form of sentient life since Treebeard does not mention them in his famous song. But then again, he didn't know of the hobbits either. Which is quite strange considering that the Stoors had lived not too far from Fangorn and that Ents may have been seen in the Shire itself (references to follow.

: PS Didn't the troll incident in the Hobbit take place in the Trollshaws? The two terms may be synonyms but I am not sure.

:::Yes, the troll incident was in the Trollshaw, but in days of old there were probably many trolls living in the Ettenmoors (perhaps they still do, but no-one knows it). As for the stone-giants, I believe that Tolkien wasn't thinking ahead as to the different types of creatures he had created, and I believe they were simply stone-trolls, and their size was exagerated. Then again, throughout Tolkien's works he speaks of "other strange creatures", and perhaps these giants are one of those that never got mentioned. I think I will post a question on the stone-trolls, and perhaps the great Michael Martinez will have an answer (he answers all my other stupid questions).
P.S., I am changing my name to Ecthelion, so from now on I am Ecthelion.