coccus vs eubacterium

coccus and eubacterium both are nouns.

Word	Noun	Adjective	Verb	Adverb
coccus	Yes	No	No	No
eubacterium	Yes	No	No	No

As nouns, eubacterium is a hypernym of coccus; that is, eubacterium is a word with a broader meaning than coccus:

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

Other hypernyms of coccus include eubacteria, true bacteria.

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