- Ptolemy, Claudius Ptolemaeus - Alexandrian astronomer who proposed a geocentric system of astronomy that was undisputed until Copernicus (2nd century AD)
--1 is a kind of astronomer, uranologist, stargazer
- Ptolemy, Ptolemaic dynasty - an ancient dynasty of Macedonian kings who ruled Egypt from 323 BC to 30 BC; founded by Ptolemy I and ended with Cleopatra
--2 is a kind of dynasty
--2 has members: Ptolemy I; Ptolemy II