n. The quality or state of being capable of causing disease.
n. The quality or state of originating or producing disease.
n. : The quality of an organism to inflict damage on the host.
The Century Dictionary and Cyclopedia
n. The state or character of being pathogenic.
Word Usage
"Before these new culture experiments had progressed very far, a very marked change in pathogenicity was observed in the Asibi virus grown in the medium, the tissue component of which was chick embryo containing minimal amounts of nervous tissue."