To scram means to leave quickly, usually because you're not wanted somewhere or because trouble is coming. If older kids tell younger ones to scram from their basketball game, they're saying “get out of here, now.” When a store owner yells “scram!” at pigeons pecking at outdoor merchandise, she wants them gone immediately.

The word carries urgency and often a hint of rudeness or dismissal. You wouldn't tell dinner guests to scram when it's time to leave; you'd politely say goodbye. But you might yell “scram!” at a raccoon digging through your trash, or tell your little brother to scram when he's bothering you and your friends.

Scram became popular American slang in the early 1900s and shows up frequently in old movies and comic books. When a character says “you better scram before the cops show up,” they mean run away fast. The word suggests both speed and the idea that staying would be a bad idea.