[probably, City].

A city of Moab, possibly its capital. It was on the S side of the Arnon Valley, but its precise location is uncertain. (Nu 21:15) At times Ar is used as synonymous with Moab. (De 2:9, 18, 29) At one time the limits of Moab extended N of the Arnon, but this region was taken from them by King Sihon of the Amorites. (Nu 21:26-28) The Israelites did not attack Moab, since Jehovah had forbidden them to do so, having given “the territory of Moab, that is, Ar,” to the sons of Lot as “a holding.” (De 2:9, 18, 29) In his pronouncement of desolations against Moab, Isaiah foretold that Ar would be “silenced” along with the other principal cities of Moab.​—Isa 15:1.

Since the name Ar probably means “City,” some suggest that the “city of Moab” (Heb., ʽir Moh·ʼavʹ) mentioned at Numbers 22:36 and also the “city” of Deuteronomy 2:36 both refer to Ar.