Green’s Dictionary of Slang

a nickname for a Jew.

1926		(con. 1900s) J.B. Booth ‘Master’ and Men 296: ‘No offence, Issey.’ ‘None taken, me old Goyisher,’ said a stout and obvious Hebrew.
1933		J.T. Farrell Gas-House McGinty 40: Billy kidded Izzy about being a Hebe.
1945		D. Bolster Roll On My Twelve 30: I’d have expected them to call him Izzy or Sheeny.
1989		H. Rawson Dict. of Invective (1991) 279: Other generics include: [...] Izzy, yet another personification for any male Jew.
2024		J. Meades Empty Wigs (t/s) 137: He despised the corporation's voracious appetite for that birthright: ‘Makes us look like Izzy Yid’.