astronomer vs Ptolemy

astronomer and Ptolemy both are nouns.

Word	Noun	Adjective	Verb	Adverb
astronomer	Yes	No	No	No
Ptolemy	Yes	No	No	No

astronomer (noun)	Ptolemy (noun)
a physicist who studies astronomy	an ancient dynasty of Macedonian kings who ruled Egypt from 323 BC to 30 BC; founded by Ptolemy I and ended with Cleopatra
	Alexandrian astronomer (of the 2nd century) who proposed a geocentric system of astronomy that was undisputed until the late Renaissance