cocci vs eubacteria

cocci and eubacteria both are nouns.

Word	Noun	Adjective	Verb	Adverb
cocci	Yes	No	No	No
eubacteria	Yes	No	No	No

As nouns, eubacteria is a hypernym of cocci; that is, eubacteria is a word with a broader meaning than cocci:

cocci: any spherical or nearly spherical bacteria
eubacteria: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of cocci include eubacterium, true bacteria.

cocci (noun)	eubacteria (noun)
any spherical or nearly spherical bacteria	a large group of bacteria having rigid cell walls; motile types have flagella