1. Caused by or altered by or manifesting disease or pathology
   "pathological bodily processes";
   - diseased, morbid, pathologic
    
2. Of or relating to the practice of pathology
   "pathological laboratory";
   - pathologic
    
3. Caused by or evidencing a mentally disturbed condition
   "a pathological liar"; "a pathological urge to succeed"

See also: neurotic, psychoneurotic, unhealthy

Encyclopedia: Pathological