Sindarin 

arthedain

place name. *Realm of the Edain

The northernmost and longest lasting of the successor-realms of Arnor after it was divided into three kingdoms (LotR/1039). Tolkien did not translate the name, but as suggested by Hammond and Scull, it might mean “Realm of the Edain” (RC/690). If so, its initial element may be a form of arthor “realm” also seen in the ancient name of Arnor, Arthor na Forlonnas “Realm of the North-harbourage” (PE17/28). The second element is almost certainly the plural Edain “(High) Men” of the noun Adan.

Sindarin [LotRI/Arthedain; PMI/Arthedain; UTI/Arthedain] Group: Eldamo. Published by

Arthedain

noun. noblemen

arth (“noble, lofty”) + edain (pl. of adan “man”)

Sindarin [Tolkiendil] Group: Tolkiendil Compound Sindarin Names. Published by

Arthedain

Realm of the Edain

Sindarin [Tolkien Gateway Atherdain] Published by

Beleg (King of Arthedain)

Beleg (King of Arthedain)

His name means "great' or "large", which may be a reference to his stature (although he may simply be named after the famous Elf of the First Age who shared this name, Beleg Strongbow).

Sindarin [Tolkien Gateway] Published by