A gaggah (or gagger in non-Rhode Islander english) is a hot dog type sandwich also known as a "Hot Weiner" served only in Rhode Island. It is a small "wiener" served on a bun, with celery salt, mustard, and a ground beef "sauce". They were made popular by "Olneyville New York System", a long standing resturant in the Olneyville section of Providence, frequnted mostly by drunks and homeless people late at night.
Person one: "Oh my god! Frank is trowing up!"
Person two: "Yeah he just ate two gaggahs all da way!"
Guy 1: "I'm drunk and hungry. Where can I get some food?!"
Guy 2: "Let's go to olneyville and get some gaggahs."