In this context, it's referring to non-Jews in general. Basically, gentiles.

Because the area had been quite Hellenized since the time of Alexander the Great and the subsequent rule of the Ptolemies and Seleucids, Greek culture was quite dominant in the region. However, Jews of the time (especially after their brief resurgence to autonomy during the Hasmonean Kingdom) divided the world into Jews and Gentiles, or Greeks, with "Greeks" referring to all the people surrounding them and living in their cities and trading with them but who were not Jews. Why "greeks"? Generally because Greek was the common language of international trade, and so foreigners would generally be seen as "greek" even if they were not from Greece proper, because that was the general culture they were affiliated with.