Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
appal is a verb meaning "strike with disgust or revulsion". It carries 2 recorded senses.
strike with disgust or revulsion
“The scandalous behavior of this married woman shocked her friends”
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”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for appal come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.