pathobiology

Short definition from Wiktionary

Noun

1. 1
   The branch of biology that deals with pathology with greater emphasis on the biological than on the medical aspects.
2. 2
   pathology (in any of its senses: study of disease, instance of disease, mechanism of disease).
3. 3
   The biologic explanations of pathogenesis, to include both pathoanatomy and pathophysiology.