Hello Joystick, you're absolutely right by pointing out that in modern Yiddish the word שמאָנצעס (YIVO: shmontses) is a pluraletantum. But in the time of borrowing this word from Western Yiddish, there used to be a singular form as well. - best regards, CaligariƆɐƀïиϠႵ 14:52, 24. Jun 2009 (MESZ)
Hi Joystick, the source is already given in the aforesaid article. According to {{Literaturliste|Kluge|sup=24}} the singular form was borrowed from Western Yiddish. - Kind regards, CaligariƆɐƀïиϠႵ 23:42, 24. Jun 2009 (MESZ)