An Elf of the first tribe, known as “The Fair” (S/53). Their name developed from the primitive root √(G)WAN “pale, fair” referring to their fair hair (WJ/383).
Conceptual Development: Tolkien also considered deriving this name from primitive ✶banya “beautiful” (PM/402) from the root √BAN (PE17/165). In Quenya, these two roots were blended, so both origins could have been true in a sense.
vanya (1) adj. "fair" (FS), "beautiful" (BAN), a word referring to beauty that is "due to lack of fault, or blemish" (PE17:150), hence Arda Vanya as an alternative to Arda Alahasta for "Arda Unmarred" (ibid., compare MR:254). Nominal pl. Vanyar "the Fair", the first clan of the Eldar; the original meaning of this stem was "pale, light-coloured, not brown or dark" (WJ:382, 383, stem given as WAN), "properly = white complexion and blonde hair" (PE17:154, stem given as GWAN); stems BAN vs. WAN discussed, see PE17:150.