What greek root most likely means from a previous time period no longer in use?

The Greek root that most likely means "from a previous time period no longer in use" is paleo-.

Here's why:

* Paleo- comes from the Greek word παλαιός (palaios), which means "old" or "ancient".

* This root is commonly used in terms like:

* Paleontology: the study of ancient life

* Paleolithic: the Old Stone Age

* Paleoanthropology: the study of human evolution

* Paleoclimate: climate of the past

Therefore, paleo- accurately reflects the idea of something belonging to a previous time period that is no longer in use.