Then, going all the way back to June, I wrote about the etymology of another toponym, Stonehenge. Funny I would have forgotten this, but Tolkien makes clear his own view in the essay, “English and Welsh”, where he writes:
There stands still in what is now England the ruinous fragment of an ancient monument that we have long called in our English fashion Stonehenge, ‘the suspended stones’, remembering nothing of its history. Isn’t the writing here wonderful? I had mentioned Old English hangian “to hang, suspend” in my discussion, and here we have Tolkien’s agreement with that theory on record. I can’t help but think he would also have liked the Hengest interpretation, as I also wrote at the time. Lucky I came across this while reading the essay again (for another purpose altogether).
 Tolkien, J.R.R. The Monsters and the Critics and Other Essays. Ed. Christopher Tolkien. London: George Allen & Unwin, 1983, p.175.