immunotoxin
noun
im·mu·no·tox·in
| \ ˈim-yə-nō-ˌtäk-sən
, im-ˈyü-nō-
\
, im-ˈyü-nō-
\
Medical Definition of immunotoxin
: a toxin that is linked to a monoclonal antibody and that is delivered to only those cells (as cancer cells) bearing the antigen targeted by the monoclonal antibody to which it is linked