Horrify a person like Revere, do we hear? (5)
I believe the answer is:
appal
'horrify' is the definition.
(I know that horrify can be written as appal)
I don't understand how the remainder of the clue works.
(Other definitions for appal that I've seen before include "Scandalise" , "Cause to be unpleasantly surprised" , "expressed dismay" , "Outrage" , "Put at rest (suspicion)" .)