It depends on the context.Candy: Suckers are lollipops.Gardening: Suckers are shoots that grow at the base of plants. They are often like branches or similar to the main stalk, but they are usually skinny, don't yield fruit, and don't contribute to the plant. They usually take energy from the main plant. So they are considered useless parts of a plant.Slang: Suckers are stupid, or gullible persons. They are often easy to take advantage of and may believe anything.