astronomer vs Sir Frederick William Herschel

astronomer and Sir Frederick William Herschel both are nouns.

Word	Noun	Adjective	Verb	Adverb
astronomer	Yes	No	No	No
Sir Frederick William Herschel	Yes	No	No	No

astronomer (noun)	Sir Frederick William Herschel (noun)
a physicist who studies astronomy	English astronomer (born in Germany) who discovered infrared light and who catalogued the stars and discovered the planet Uranus (1738-1822)