Elros in Quenya is Elerosse, another example of
Both the names of Elrond and Elros were made to resemble their mother's name, Elwing. The term "-wing" has no apparent meaning that I know of; it is thought to be influenced by the tongue of Ossiriand.
Elros was the first king of the Dunedain of Numenor,
twin brother of Elrond,
appointed by the Valar.
Elros was a half-elf given the Choice of the Half-elven because of the service of his father, Earendil, to the Valar and the Eruhini. Elros chose to be a Man, while his twin brother Elrond chose to be an Elf.
Elros' son, Vardamir, succeeded him as king of Numenor.
Reference: Return of the