Point of information:

There is no such language as "Jewish".

There's Hebrew, spoken today primarily in Israel, and Yiddish, which is very similar to German, and was quite popular among European Jews prior to World War II and is pretty much a dying language today, although it is still alive in the large New York City Hasadic community which is comprised largely of European immigrants.

Anyway, "bubkis" is Yiddish, and means "nothing".