What is the Greek word for evolve?

There isn't a single perfect Greek word that translates directly to "evolve" in the modern biological sense. The concept of biological evolution is a relatively recent one. However, depending on the nuance you want to convey, several words could be used:

* εξελίσσομαι (exelissomai): This is probably the closest single word. It means "to develop," "to unfold," or "to progress," and encompasses the idea of gradual change over time. This would be a suitable choice in many contexts.

* μεταβάλλω (metaballo): This means "to change" or "to transform." While not specific to biological evolution, it captures the essence of change that is central to the process.

* You might also use a phrase to be more precise, such as βιολογική εξέλιξη (biologiki exelisi) which literally translates to "biological evolution."

The best choice depends on the context. If you're writing about biological evolution, εξελίσσομαι (exelissomai) or the phrase βιολογική εξέλιξη (biologiki exelisi) are probably the most appropriate.