n.
Any of various large differentiated T cells that recognize and lyse target cells bearing a specific foreign antigen, usually by infection with a virus, and that also function in defense against cancer cells. Also called cytotoxic T cell, killer T cell.
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.