appall in WordNet English dictionary

1. fill with apprehension or alarm; cause to be unpleasantly surprised
   "I was horrified at the thought of being late for my interview"; "The news of the executions horrified us"
   dismay  alarm  appal  appall  horrify 
   
2. strike with disgust or revulsion
   "The scandalous behavior of this married woman shocked her friends"
   shock  offend  scandalize  scandalise  appal  appall  outrage