What does the root of this word mean archaic?

The root of the word "archaic" is "arkhaios", which is a Greek word meaning "ancient" or "primitive".

This root is reflected in other words like:

* Archaeology: The study of ancient cultures.

* Archipelago: A group of islands, originally referring to the Aegean Sea, considered ancient.

Therefore, "archaic" essentially means "belonging to an ancient time period" or "outdated" because of its age.