solar system vs Venus

solar system and Venus both are nouns.

Word	Noun	Adjective	Verb	Adverb
solar system	Yes	No	No	No
Venus	Yes	No	No	No

solar system (noun)	Venus (noun)
the sun with the celestial bodies that revolve around it in its gravitational field	type genus of the family Veneridae: genus of edible clams with thick oval shells
	the second nearest planet to the sun; it is peculiar in that its rotation is slow and retrograde (in the opposite sense of the Earth and all other planets except Uranus); it is visible from Earth as an early `morning star' or an `evening star'
	goddess of love; counterpart of Greek Aphrodite