A sandwich in a long roll. Used primarily in Southern New England.
-Can you get me a turkey grinder, Jethrow?
-What is a grinder, sir?
-Sorry Jethrow, I forgot that you're an illiterate southener. A grinder is the same as a sub, a hoagie, or a hero.
-I understand now. I'll make you a grinder now. Thank you kindly.