Well, this term is applied to the priesthood of the New Testament:
"Let a man so account of us, as of the ministers of Christ, and stewards of the mysteries of God."
(1Cor:4:1)
BTW, I would rather say that it was New Testament Greek which influenced Aramaic. Educated Jews/Christians of that time used Greek, especially outside of Palestine (in ALexandria or Rome). So they used Greek version of Old Testament Scriptures (Septuaginta) and so the New Testament was in Greek.
Educated Jews never used the Septuagint. The Septuagint was written mostly for Jews outside Judea who had forgotten Hebrew.
The word "natsur" has meaning in Hebrew and Aramaic. It appears in Isaiah 48:6. It is translated in English language bibles as "hidden things." Isaiah was written long before anyone in Judea spoke Greek.
The word "nazoraios" has no root in Greek. It is obviously from a foreign root. So it could not have come from Greek into Aramaic. Just the opposite. But it most likely did not come from the town of Nazareth as the New Testament implies.
"Steward of the mysteries of God" is a plausible explanation of what it might mean.