An adjective for “golden” mentioned in Tolkien’s “Unfinished Index” of The Lord of the Rings as an element in the name Cormallen “Golden Circle” (RC/625). It may also be seen in Rathmallen, a variant of the name Rathlóriel “Golden-bed”, replacing the second element glóriel “golden” with mallen (WJ/353). The word N. mallen also appeared in The Etymologies of the 1930s under the root ᴹ√SMAL “yellow” as an “analogical” variant of N. malthen “of gold” (Ety/SMAL).
Possible Etymology: In Tolkien’s later writings, this adjective was probably based on the root √MAL(AT) “gold”, also seen as the basis for the noun malt “gold [as metal]” (PE17/50; VT42/27). It was likely in keeping with the 1950s and 60s sound change whereby medial lth became voiceless ll; a similar sound shift may be seen in S. mallorn “golden tree” < OS. malthorn = malt + orn (VT42/27). In Noldorin of the 1930s lth was preserved, so 1930s N. mallen may have been based on ✱(s)maldina instead.
Neo-Sindarin: For purposes of Neo-Sindarin, I would use this word only for golden colors, and would use [N.] malthen for “of gold [metal]”; see that entry for discussion.
adj. #golden. This word is not explicitly presented as S. >> malh, mallorn