A word for “moon”, equivalent of Q. Rána, attested in later writings only as the element -rawn in the archaic form S. †cýrawn “new-moon”, in modern speech cýron (VT48/7). Based on its use in this word, as well as in N. cúran “crescent moon” [ᴺS. cúron], it seems this is the ordinary word for “Moon” (or “moon”) as a celestial body, as opposed to S. Ithil which is the proper name of the moon, equivalent to English “Luna”. Raun is derived from primitive ✶rānā from the root √RAN “wander”, and hence originally meant something like “Wanderer”, though its Quenya equivalent is usually translated “Wayward”.
Conceptual Development: A very similar form G. Rân “the moon” appeared in Gnomish Lexicon of the 1910s (GL/64), as well as ᴱN. rán “moon” in Early Noldorin Word-lists of the 1920s (PE13/152), though in this period its etymology is unclear. It appeared as N. Rhân “Moon” in The Etymologies of the 1930s, derived from the root ᴹ√RAN “wander, stray” (Ety/RAN), but in this period its Quenya equivalent was ᴹQ. Rana with short a. In later writings the Quenya form became Q. Rána, requiring a change to S. Raun since ancient ā became au in Sindarin.
The usual name for the Moon in Sindarin, from an augmented form of the root √THIL (Let/425; Ety/THIL). This word is most likely the proper name of the Moon, analogous to English “Luna”: in The Etymologies of the 1930s Tolkien indicated Ithil was a “poetic name”. Compare this to S. Raun “Wanderer”, which is more descriptive of the nature of the body and hence closer to “Moon” (and “moon”).
Conceptual Development: The first precursor to this name seems to be G. Thilim “Moon” in an early list of names (PE14/13). This became G. {Thil >>} Sil “Rose of Silpion, Moon” (GL/67, 72) and G. {Thilmos >>} Silma in the Gnomish Lexicon of the 1910s (GL/33, 67), both derivatives of the early root ᴱ√SILI as suggested by Christopher Tolkien (LT1A/Sil). The name Ithil first appeared in early versions of the tales of Númenor from the 1930s (LR/41).