A cyborg is someone who combines human and machine parts, or an imaginary being that's part human and part robot.
You might have seen pictures of superheroes with metal arms and legs. That's basically a real-life version of a cyborg. But it doesn't always have to be about physical parts - sometimes in science fiction, like in movies or books, people imagine what would happen if we merged humans and machines even further.
(science fiction) A being which is part machine and part organic.
Example: I would not classify the Tin Woodman as magical robot, but more of a magical cyborg, if anything.
