from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A bag for leftover food that a customer of a restaurant may take home after a meal.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A bag (or other container) used to take home uneaten food from a restaurant meal.
- n. A bag used to pick up the droppings of dogs in parks and public places.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a bag for food that a customer did not eat at a restaurant; the transparent pretense is that the food is taken home to feed the customer's dog
From the assumption that such food would be given to the customer's dog.(American Heritage® Dictionary of the English Language, Fourth Edition)