mycoplasma Syllabification: (my·co·plas·ma)Pronunciation: /ˌmīkōˈplazmə/Definition of mycoplasma noun (plural mycoplasmas or mycoplasmata /-mətə/) any of a group of small typically parasitic bacteria that lack cell walls and sometimes cause diseases. Class Mollicutes and order Mycoplasmatales mycoplasma in other Oxford dictionaries Definition of mycoplasma in the British & World English dictionary