Twin brother of Amrod and second(?) youngest of the sons of Fëanor (it is unclear which of the twins was born first). The name is a compound of am “up” and ross “red-haired” (PM/353, VT41/10), an adaption of his Quenya nickname Q. Ambarussa. In a few places the name appears as Amros (PM/366, VT41/10), closer to its Sindarin elements.
Conceptual Development: In the earliest Lost Tales, this character was first named G. Dinithel (LT2/251), revised in the Lays of Beleriand to ᴱN. Durithel, then ᴱN. Díriel (LB/86). The name remained N. Díriel in Silmarillion drafts from the 1930s, and the form Diriel (with a short i) appeared in The Etymologies (Ety/DER, GYEL). The name was revised to Amras in Silmarillion revisions from the 1950s-60s (WJ/197).
A word glossed “rising, soaring, lofty” in Early Noldorin word lists of the 1920s derived from ᴱ✶amba-ros-sa, so originally “✱up rising” (PE13/137, 159). One of these lists had a deleted form annuir “lofty” (PE13/137), probably a callback to G. annuir “lofty” in Gnomish Lexicon Slips from the 1910s derived from ᴱ✶amsŏrı̯a (PE13/110). This in turn had replaced {andor >>} G. annor(in) in the Gnomish Lexicon proper, equivalent to G. anthor(in) “lofty (of mountains)”, the latter influenced by [deleted] G. anthos “up, above” (GL/19).