Name of the Maia who guided the moon (S/99). This name was translated “Horned” or (Old English) “Hyrned” (MR/130, 136) and its initial element is derived from the root √TIL “point, horn” (SA/til, Ety/TIL). The meaning of the second element is unclear, but it could simply be the genitive plural ending, so that Tilion = “✱of the horns”.
Conceptual Development: In the earliest Lost Tales, this character was named ᴱQ. Ilinsor (LT1/192), but the meaning of this early name is unclear. In Silmarillion drafts from the 1930s, his name changed to ᴹQ. Tilion “Hyrned” (SM/97, LR/240). In The Etymologies from the 1930s, this name was glossed “Horned” and was a derivative of ᴹ√TIL “point, horn” (Ety/TIL), which is the basis of the derivation given above (both the translation “Horned” and the root √TIL also appeared in later writings).
Noldorin equivalent of ᴹQ. Tilion appearing only in The Etymologies from the 1930s (Ety/TIL), a combination of till “horn” and an adjective suffix -(i)on (assuming it is not simply a direct adaptation of his Quenya name).