Musicologists, klezmer musicians, and J-music bloggers will try to fool you into thinking it's a unique scale and not just a mode of harmonic minor. That's just a story.
The real truth is that the term was popularized by a now-forgotton American clarinet player who once approached legendary klezmer clarinetist Naftule Brandwein to ask about the scale. "Freyg Nisht", the notoriously secretive Brandwein replied. Not understanding Yiddish, the hapless American took that as the name and shared his corrupted pronunciation of it, "Freygish" with all who asked. And that's why American club date musicians call it "Freygish. #DoIReallyHaveToLabelThisOne?
Apparently, I do have to label this one. It's fiction, folks. follow the link for more info about Freygish.