Ah, so you got round to creating this thread,
Lal.
As has already been said, I think we should take any similarity with existing English (or Welsh, Finnish or Latin) words with a pinch of salt. The purpose of Tolkien's invented language was to be beautiful, not to reflect English. Thingol is probably no more than the sum of his Sindarin parts.
Entmoot, meanwhile, is presented as the English equivalent of a Westron word. It makes sense that it should reflect English, or Old English, or any Inbetween English. I found the exploration of its root very interesting. So, thanks to Lal for creating the thread, and Squatter for knowing Old English!
EDIT:
This thread is worth a look for name jokes.