Simple definition-a sandwich, sub sandwich, or other variant.
Variations- scamwich, slammich, slamwich (first syllable varies)
Uses-for general public confusion and/or to make it sound better than/
more manly than getting a "sandwich".
Angry guy: "hey stop pushing your way into the hot line!"
You: "sorry dude I was just heading for the scammich line."
angry guy: "what? What the hell is a scammich?"
you: "sandwich, bro."
angry guy: "oh, go right ahead."