What does "marauder" mean?

Native speaker’s answer
Rebecca
A "marauder" is a person who is a raider, looter, or bandit. In essence, a person who roams far distances to plunder (steal) people and things. In Harry Potter, this term is used rather loosely as they're not actually intending to do things that are harmful to others. It's meant here in a playful way, to make their activities seem a little "cooler." Ex: The marauders were famous for robbing caravans traveling along the highway. Ex: The Great Wall of China was built to keep out marauders and raiders.