Real Dictionary

mycoplasma in American English
any of a class (Mollicutes) of bacteria that lack cell walls and may cause disease, esp. of the joints and lungs, in humans and domestic animals, or may be pathogenic for plants
noun: any of numerous parasitic microorganisms of the class Mollicutes, comprising the smallest self-reproducing prokaryotes, lacking a true cell wall and able to survive without oxygen: a common cause of pneumonia and urinary tract infections

mycoplasma in British English
noun: any prokaryotic microorganism of the genus Mycoplasma, some species of which cause disease (mycoplasmosis) in animals and humans