Quote Originally Posted by Doomer View Post
That's incorrect
Ништяк comes from criminal jargon that has many "Jewish" words in it
Ништяк(от ивр. נשתק ништак - мы успокоимся) - здорово, отлично.
the source is Русская "феня", говорящая на идиш

as Hebrew it doesn't sound cause there's no such word as נשתק - nishtak, there's נשתוק - nishtok meaning we will go silent, we will stop talking, so could be Yiddish