Define Four-finger Discount Meaning

What Jimbo in the Simpsons calls shoplifting. (All Simpsons characters have four fingers on each hand.)

The term for an animated character shoplifting as they only have 4 fingers on each hand

When a young man procures free or discounted items from a female food service worker by letting his fingers do the walking.
-This act can be performed under a table, in a kitchen, or in a bathroom. Just remember to always wash your hands before handling the food.