A nanobot is a machine that can move and do jobs, but it is so small you would need special equipment — a microscope, for example — to see it. You meet the word mainly in stories and films about the future, and in talk about what science might one day build. Though actually, in real laboratories people more often say nanomachine or talk about nanotechnology; nanobot has a sci-fi flavour, as if the tiny thing were a little robot with a job of its own. Nano- here means 'extremely small'. It is a science-and-story word, not something you would say about a toy.

奈米機器人（多半是科幻說法。台灣用「奈米」，中國大陸用「納米」）