From Yiddish שמעגעגע (shmegege).
schmegeggy (plural schmegeggies)
- an idiot, a dickhead
1969, Philip Roth, Portnoy's Complaint:
- Her lover she calls me, while her husband is listening on the other extension! And it never occurs to her, if I’m her lover, who is he, the schmegeggy she lives with?