The 2nd chieftain of the Dúnedain (LotR/1038). The initial element of his name is the prefix ar(a)- “noble” and its final element might be the lenited form hael of the adjective sael “wise”.
Conceptual Development: In the draft of Appendix A of the Lord of the Rings, his name was first given as Araha[n]til (6th letter illegible), revised to Arahail (PM/211). The name was changed to Arahael for the published version of The Lord of the Rings.
ara (prefix “high, noble, royal”) + sael (“wise”)