<p><strong>Noun</strong></p><ul><li>A little world; a world in miniature (macrocosm): The human body is a microcosm.</li><li>Anything regarded as a representative, miniature version of a larger complex reality: The fictional small town of Black Rock, California, serves as a microcosm of America in the postwar era.</li><li>Environmental Science: A controlled experimental environment or ecosystem small enough to be housed in a laboratory and reproducing conditions that occur on a larger scale in the outdoors: Compare mesocosm (def).</li><li>Researchers have investigated the survival of this bacteria in saline solutions and seawater in laboratory microcosms.</li><li>Human beings, humanity, society, or the like, viewed as an epitome or miniature of the world or universe: In the human microcosm, intellect is the deep spiritual center of being.</li></ul>