appall

US: /əˈpɔl/ ,(ə pôl′)

WordReference Random House Learner's Dictionary of American English © 2026

ap•pall or ap•pal /əˈpɔl/   v. [~ + object] , -palled, -pall•ing. 

1. to fill or overcome with horror, shock, or fear;
   dismay greatly:
   The terrible fire appalled the neighbors.

WordReference Random House Unabridged Dictionary of American English © 2026

ap•pall  (ə pôl′), v.t. 

1. to fill or overcome with horror, consternation, or fear;
   dismay:
   He was appalled by the damage from the fire. I am appalled at your mistakes.
   Also, appal. 

• Middle French ap(p)allir to grow or make pale, equivalent. to a- a-⁵ + pal(l)ir in same sense; see pale¹
• Middle English 1275–1325

Synonyms

horrify, daunt. See frighten. 

WordReference Random House Unabridged Dictionary of American English © 2026

ap•pal  (ə pôl′), v.t., -palled, -pal•ling. 

1. appall.

Collins Concise English Dictionary © HarperCollins Publishers::

appal, appall / əˈpɔːl/ verb ( -pals, -palling, -palled) ( -palls, -palling, -palled)

1. (transitive) to fill with horror; shock or dismay

Etymology: 14th Century: from Old French appalir to turn pale