The word númen or núme was the Quenya word for “west” for much of Tolkien’s life, and was also the name of tengwa #17 (LotR/1123). It is a combination of √N(D)Ū “go down” and √MEN “way” (PE17/64; Ety/NDŪ, MEN), so originally meaning “going down” or “way of the setting sun” (Let/361) in the same way that rómen “east” is the direction of the rising sun. Q. númen is thus similar in origin to English “occident”. As a standalone word it is usually númen, but in compounds or with inflections it is frequently reduced to núme-. For the Elves, númen is considered the primary direction, since it points towards Aman where the Two Trees were (LotR/1123; VT49/8).
Conceptual Development: ᴱQ. nūme “west” dates all the way back to the Qenya Lexicon of the 1910s where it appeared under the early root ᴱ√NUHU “bow, bend down. stoop, sink” (QL/68). The form númen did not appear as an independent word until The Etymologies of the 1930s (Ety/MEN), and númen was already the name of tengwa #17 in the earliest version of notes on The Feanorian Alphabet (PE22/23).
númen noun "west, the way of the sunset" (SA:andúnë, cf. NDŪ, MEN; capitalized Númen under SA:men and in CO), "going down, occudent" (Letters:361), also name of tengwa #17 _(Appendix E). _According to VT45:38, the word is actually cited as "nú-men" in Tolkien's Etymologies manuscript. Allative númenna "Westward" (LR:47, SD:310, VT49:20, capitalized Númenna, VT49:22; numenna with a short u, VT49:23); adj. númenquerna "turned westward" (VT49:18, 20). See also númenyaron, númessier. - In the pre-classical Tengwar system presupposed in the Etymologies, "nú-men" was intended as the name of tengwa #21, to which letter Tolkien at this stage assigned the value n (VT45:38). However, this tengwa was later given the Quenya value r instead and was renamed órë.