Since this word is placed in the mouth of Laban, it may be an Aramaism of Akkadian background.
Akkadian words borrowed through Aramaic are for all intents and purposes Aramaisms, having the same historical significance for dating documents as simple Aramaisms.
Because the root kbr is relatively common in Samalian,(1) Old Aramaic,(2) and Middle Aramaic,(3) and yet rare in Biblical Hebrew (BH), one might be inclined to view kabbir as an Aramaism in the Bible.
Biblical scholars still are not agreed as to what constitutes an Aramaism.
Kaufman noted that in a number of famous instances the speech of Transjordanians is tinged with unusual grammatical forms and rare lexical items, many of which typically are classified as Aramaisms.
If it appears that I am arguing on the one hand for Aramaisms in Job and on the other hand for Arabisms in Job, let me again quote Kaufman in this regard: "the dialects of the early 'Arabs,' which by and large are what our authors are trying to replicate here, were much closer to Aramaic.
14) Given the widespread use of Aramaic in the Neo-Assyrian empire,(15) Isaiah peppered the Assyrian king's orations with Aramaisms to represent his speech as foreign.