/an"ti bod'ee/ , n. , pl. antibodies .
1. any of numerous Y-shaped protein molecules produced by B cells as a primary immune defense, each molecule and its clones having a unique binding site that can combine with the complementary site of a foreign antigen, as on a virus or bacterium, thereby disabling the antigen and signaling other immune defenses. Abbr.: Ab
2. antibodies of a particular type collectively. Also called immunoglobulin .
[ 1895-1900; ANTI- + BODY ]