n.
An antibody or product of complement activation in blood serum that causes bacteria or other foreign cells to become more susceptible to the action of phagocytes.
[Latin opsōnāre, to buy provisions (from Greek opsōnein , from opson, condiment, delicacy) + -IN.]
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.
