Another name of Taniquetil (S/37), a compound of elen “star” and rína “crowned”. The final -n of elen was assimilated to the r, which also happened in the names Elerondo and Elerossë.
Conceptual Development: This name first appeared in Silmarillion drafts from the early 1930s as ᴹQ. Tinwenairin (SM/81) using the earlier word ᴹQ. tinwe for star. In drafts from the mid-30s the name was changed to ᴹQ. Tinwerína and then ᴹQ. Elerína (LR/209, 210). Both of these names appeared in The Etymologies, Tinwerína as a derivative of ᴹ√RIG (Ety/RIG) and Elerína in a later marginal note near ᴹ√EL (Ety/EL). The form was changed to Elerrína with two r’s in Silmarillion revisions from the 1950s-60s (MR/154) and remain so thereafter, though Tinwerína briefly reappeared in some notes from the 1950s (PE17/182).
Elerrína adj. used as noun: "Crowned with Stars" (elen + rína), a name of Taniquetil (Silm); spelt Elerína in the Etymologies (EL, RIG).