Any of numerous parasitic, pathogenic microorganisms of the genus Mycoplasma that lack a true cell wall, are gram-negative, and need sterols such as cholesterol for growth. In humans, one species is a primary cause of nonbacterial pneumonia. Also called pleuropneumonia-like organism.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.