|  | 
Definition of Ptolemy I
1. Noun. The king of Egypt who founded the Macedonian dynasty in Egypt; a close friend and general of Alexander the Great who took charge of Egypt after Alexander died (circa 367-285 BC). 
|  | 
1. Noun. The king of Egypt who founded the Macedonian dynasty in Egypt; a close friend and general of Alexander the Great who took charge of Egypt after Alexander died (circa 367-285 BC).