Southern Cross vs constellation

Southern Cross and constellation both are nouns.

Word	Noun	Adjective	Verb	Adverb
Southern Cross	Yes	No	No	No
constellation	Yes	No	No	No

Southern Cross (noun)	constellation (noun)
a small conspicuous constellation in the Southern Hemisphere in the Milky Way near Centaurus	an arrangement of parts or elements
	a configuration of stars as seen from the earth