IPA: /əˈpɔːlɪŋ/
KK: /əˈpɔlɪŋ/
Causing shock, horror, or strong disapproval; very bad or unpleasant.
The appalling conditions in the shelter shocked everyone who visited.
Comparative: more appalling
Superlative: most appalling
Appalling is formed from "appall" (from Old French *apalir*, meaning to make pale or to frighten) and the suffix "-ing" (indicating the action or process). The word "appalling" describes something that causes shock or dismay, often to the point of making one feel pale or frightened.
Think of something that makes you feel so shocked or frightened that it leaves you feeling pale — that's what appalling means.