Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unmodifiable is an adjective meaning "incapable of being modified in form or character or strength (especially by making less extreme)". It carries one recorded sense.
incapable of being modified in form or character or strength (especially by making less extreme)
“these variations from custom are illogical, incomprehensible, and unmodifiable”
Definitions, synonyms and semantic relations for unmodifiable come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.