terrestrial vs Earth

terrestrial is not a noun while Earth is a noun.

Word	Noun	Adjective	Verb	Adverb
terrestrial	No	Yes	No	No
Earth	Yes	No	No	No

terrestrial (noun)	Earth (noun)
	the abode of mortals (as contrasted with Heaven or Hell)
	the 3rd planet from the sun; the planet we live on

terrestrial (adjective)	Earth (adjective)
operating or living or growing on land
of or relating to or inhabiting the land as opposed to the sea or air
of or relating to or characteristic of the planet Earth or its inhabitants
of this earth
concerned with the world or worldly matters