This is a common form from Mishnaic Hebrew (see Jastrow pp. 89f.), itself apparently a corruption of an otherwise unkown Greek word combining the words for "star", i.e. astro- with "knower", i.e., gnō. Levy’s proposed etymology ὁ στεγανος makes little sense in the contexts. Note that all the other versions use the standard Aramaic word for "sorcerer", i.e., ḥrš in these passages. Apparently PsJon wanted to use a foreign-sounding word to reflect the obviously foreign word in BH, but more importantly wanted to distinguish between the dream interpreting function of the Hebrew term in the Genesis passages, for which he uses the standard חרש, and the magical actions here. Page refs. in other dictionaries: Jastrow: 89; Levy Ch-W: 1:44;