morning star vs Phosphorus

morning star and Phosphorus both are nouns.

Word	Noun	Adjective	Verb	Adverb
morning star	Yes	No	No	No
Phosphorus	Yes	No	No	No

As nouns, morning star and Phosphorus are synonyms defined as:

morning star and Phosphorus: a planet (usually Venus) seen just before sunrise in the eastern sky

Other synonyms of morning star include daystar, Lucifer.

morning star (noun)	Phosphorus (noun)
a planet (usually Venus) seen just before sunrise in the eastern sky	a planet (usually Venus) seen just before sunrise in the eastern sky