Allar is a place found only in the Apocrypha. This is another difficult word to track down.

1 Esdras 5:36 “These came up from Thermeleth and Thelersas, Charaathalar leading them, and Aalar;”

It is a place that we don’t really know a whole lot about.

Allar. al´ar (the King James Version, Aalar; Ἀαλάρ, Aalár):
Alternate spelling of aalar.

Occurring once (1 Esdras 5:36) and used apparently to indicate a place from which certain Jews came on the return from captivity, who could not prove their lineage, and were excluded for this reason from the privileges of the priesthood. HDB identifies with Immer of Ezr 2:59 and Neh 7:61 (which see), but this is not at all certain.

[ISBE]