Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unappealable is an adjective meaning "not subject to appeal". It carries one recorded sense.
not subject to appeal
“the judge's ruling was handed down in a preliminary hearing rather than a trial and was therefore unappealable”
Definitions, synonyms and semantic relations for unappealable come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. .