What does Constellation mean in greek or latin?

The word "constellation" comes from the Late Latin word *constellatio*, which literally means "a setting together of stars." It's a combination of:

* con-: A prefix meaning "together" or "with."

* stella: Latin for "star."

Therefore, its root meaning reflects the visual grouping of stars that we recognize as constellations. There isn't a direct equivalent single word in classical Greek with precisely the same meaning, but the concept was expressed through descriptive phrases.