A crop is an organism that is dependent on, and exclusively serves the interests of, the dominant human society. A weed is an organism that is not dependent on human society, and that collaborates with wider interests. Sometimes the dominant society gives crops manufactured advantages, such as genetically engineered resistance to human-manufactured poisons. When a weed acquires one of these advantages, or when a crop with one of these advantages escapes from human cultivation, it's called a superweed.