When someone tosses someone else's salad, but uses jelly or preserves instead. It is unclear why this is called a "peanut butter and asshole sandwich" if it has no peanut butter, but it does have a ring to it.
When giving people a peanut butter and asshole sandwich, strawberry jam should be avoided because of the tiny seeds.
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.