Yes - I knew exactly what it meant from the thread title. My family and friends didn’t use that expression though. I think I learned it from a book I read at some point when I was 10 or so.
ETA: I grew up in the southeastern US if that makes a difference.
Never heard it used but have seen it in print more than once over 10 years ago. I can’t recall what novels it was in but it struck me as a clever little phrase.
Never heard it, either, but I assume it means the leftover crust edges. Thing is, I actually don’t know anyone offhand I eat pizza with that leaves the crust. The wife & I certainly don’t.