What does demo mean in greek?

The word "demo" doesn't have a direct translation in Ancient Greek that means "demo" in the modern sense of a demonstration or sample. The modern English word "demo" is a shortened form of "demonstration," which itself has Latin roots.

However, the Greek word δήμος (dēmos) is the root of the English word "democracy." Δῆμος refers to the common people, the citizenry, or a district. So, while not a direct translation of "demo" as in "demolition" or "product demo," δήμος is etymologically related to the concept of the public which is sometimes involved in demonstrations.