n.
A mild contagious skin disease of cattle, usually affecting the udder, that is caused by a virus and characterized by the eruption of a pustular rash. When the virus is transmitted to humans, as by vaccination, it can confer immunity to smallpox. Also called vaccinia.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
