nar

root. fire, fire, [ᴹ√] flame

A root for “fire” first appearing as ᴹ√NAR “flame, fire” in The Etymologies of the 1930s along with derivatives like ᴹQ. nár(e)/N. naur “flame” (Ety/NAR¹). There was also an augmented variant ᴹ√ANÁR that served as the basis for “Sun” words: ᴹQ. Anar and N. Anor (Ety/ANÁR). These roots and the various derivatives continued to appear in Tolkien’s later writings in the 1950s and 60s (PE17/38; Let/425), and in one place Tolkien specified that nār- was “fire as an element” as opposed to √RUYU for an actual blaze.