Cooked balls of dough. They are based on flour, potatoes or bread, and may include meat, fish, vegetables, or sweets. They may be cooked by boiling, steaming, simmering, frying, or baking. They may have a filling, or there may be other ingredients mixed into the dough.
Dumplings are what's left of your shit that doesn't go down the toilet post flush. The remaining microturd will linger in the bowl until a 2nd flush is performed, and if not in a timely fashion can result in a rotten fart funk that will linger in the bathroom for an unfortunate person to find.
Make sure you courtesy flush because the plumbing here sucks, I don't want you leaving a dumpling here for me to find later.