A sandwich that contains all aspects of a large dinner.
For instance: With a roast/Sunday dinner, one may put mashed potato, carrots, roast potato, chicken (or whatever meat you have) and possibly a Yorkshire pudding.
The kinds of Grandwiches are endless.
Bill: Man, I just chowed down on the most epic Grandwich!
Bob: ... Grandwich?
Bill: Yeah! The sandwich of all aspects; The Grandwich! It is legion, it does not forgive, it does not forget. Expect it.
noun
1. a small woodland creature which is either of the groundhog or woodchuck family.
2. an alcoholic beverage in shot form with hot sauce and tequilla, the end result is often an upchuck.