be·smirch
 /bıˈsmɚʧ/  verb  , -smirch·es, -smirched, -smirch·ing [  + obj  ]
  : to cause harm or damage to (the reputation of someone or something)
   He has besmirched [=sullied] her reputation/name/honor by telling lies about her. [=he has caused people to have a low opinion of her]