The Quenya name of S. Orodreth in some of Tolkien’s later writings (PM/346, 350). It is a compound of the prefixal form arta- of arata “noble” and heru “lord”.

Conceptual Development: His Quenya name was initially Artanáro, but this was changed to Artaresto, while Artanáro became the Quenya name of his son Gil-galad (PM/350). Later, the name was changed again to Artaher and its Sindarin form to S. Arothir, which was probably meant to replace S. Orodreth in The Silmarillion, although Tolkien did not get around to making those changes. The name Artaresto is more compatible with his Sindarin name Orodreth in the published version of The Silmarillion.

The Quenya name of S. Orodreth in some of Tolkien’s later writings (PM/350). This name was Sindarized as S. Rodreth (Arta- > Rod- and -resto > -reth), and then further modified to Orodreth “because of his love of the mountains” (PM/350). The initial element of Artaresto is the prefixal form arta- of arata “noble”. An alternate Sindarin form might be Arodreth “Noble Endurance” (PE17/182), suggesting its second element resto might be based on √RETH “remain in same place” and mean “endurance”; hat-tip to Vyacheslav Stepanov for this suggestion.

Conceptual Development: In later notes, his Quenya name was changed to Artaher and his Sindarin name to S. Arothir, but these changes were not made in The Silmarillion narratives and the status of these later names is unclear (PM/350).