Horner’s syndrome n. A syndrome caused by a lesion in the sympathetic nervous system, especially the cervical chain or central pathways, and characterized by drooping upper eyelid, pupillary contraction, absence of sweating, and receding eyeball. Liberaldictionary.com
The American Heritage® Stedman’s Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.