mycoplasma vs eubacterium

mycoplasma and eubacterium both are nouns.

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

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

mycoplasma: any of a group of small parasitic bacteria that lack cell walls and can survive without oxygen; can cause pneumonia and urinary tract infection
eubacterium: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of mycoplasma include eubacteria, true bacteria.

mycoplasma (noun)	eubacterium (noun)
any of a group of small parasitic bacteria that lack cell walls and can survive without oxygen; can cause pneumonia and urinary tract infection	a large group of bacteria having rigid cell walls; motile types have flagella