berrysphase
I feel like I have to apologize to JRRT every time I post one of these things but guys, guys, you know the bit in the Lay of Leithian where Sauron is trying to figure out the names and quests of his captives — look, I will let Chris Tolkien say it,
The name Dungalef (2121), though it sounds Orcish enough, was an oddly transparent device, since Felagund had just been mentioned; but it succeeded (2217). No doubt [Sauron]’s ponderings on the matter were too subtle.
Please note that Beren is giving his name as Nereb right now.