sucker

A sucker is something that sucks, in the sense that it sucks fluid from something.

Example: Mosquitos are blood-suckers.

A sucker is someone who is easy to trick or deceive. They are gullible.

A sucker is another word for a lollipop. It can also mean any candy that you suck on.

If someone is a sucker for something or someone, they are very attracted to it.

Example: I'm always a sucker for horror stories.