the absence of antibody production in response to the presence of antigens, usually as a result of previous exposure to the antigens
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Acquired specific failure of the immunological mechanism to respond to a given antigen, induced by exposure to the antigen.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.