§ Elements in Quenya and Sindarin Names The Silmarillion

ar(a)- 'high, noble, royal' appears in a great many names, as Aradan, Aredhel, Argonath, Arnor, etc.; extended stem arat- appearing in Aratar, and in arato 'champion, eminent man', e.g. Angrod from Angaráto and Finrodfrom Findaráto; also aran 'king' in Aranrúth. Ereinion'scion of kings' (name of Gil-galad) has the plural of aran; cf. Fornost Erain 'Norbury of the Kings' in Arnor. The prefix Ar- of the Adûnaic names of the Kings of Númenor was derived from this.