What does Bartimaeus mean in Greek?

Bartimaeus isn't a Greek name; it's Aramaic. The name is composed of two elements: "Bar" (son of) and "Timaeus." While "Bar" has a direct equivalent in Greek, "Timaeus" itself is of Greek origin. Therefore, there isn't a direct Greek translation, but a transliteration or interpretation depending on context. It could be interpreted in Greek as something like "Son of Timaeus," using the Greek word for "son" (υἱός - *huios*) along with the existing Greek name Timaeus.