A highly infectious viral disease that chiefly affects children and, in its acute forms, causes inflammation of motor neurons of the spinal cord and brainstem, leading to paralysis, muscular atrophy, and often deformity. Through vaccination, the disease is preventable. Also called infantile paralysis.
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.