When you crave crunchy or sweet snacks, you've got the munchies. Be sure to stock up on chips and ice cream before your friends come over for movie night, in case they get the munchies.
When someone has the munchies, they aren't hungry enough for a meal, but they desperately want to eat some snacks. You can also use this word for the snacks themselves: "Did anyone remember to bring munchies for the party?" In its singular form, munchie, this word has been around since the early 20th century, from munch, "chew continuously."