Probably the Quenya name of S. Elrond, attested only in the names Elerondiel and (rejected) Elerondorel for his daughter Arwen (PE17/56). These two names probably meant “✱Daughter of Elrond”. The name Elerondo was therefore probably a compound of elen “star” and rondo “vaulted roof”, a direct translation of S. Elrond. The final -n of elen was probably assimilated to the r, which also happened in the names Elerossë and Elerrína.
Quenya
Elerondo
star-vault
elerondo Reconstructed
masculine name. Elrond, (lit.) Star-dome
*Elerondo masc_. _name "Star-vault", Sindarin Elrond. Extrapolated from Elerondiel "daughter of Elrond", patronym of Arwen (PE17:56); cf. Elerossë, rondo.