Affected by strong feelings of shock and dismay. (Merriam -Webster)
If you are appalled by something, you are shocked or disgusted because it is so bad or unpleasant. (Collins Dictionary)
Very bad. (Cambridge Dictionary)
Shocking and very bad. (Cambridge Dictionary)
Greatly dismayed or horrified. (Oxford Dictionaries)
Appalled. Slide Player.
Appalled. Word pandit.