Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unshakably is an adverb meaning "with determination; in a determined manner". It carries one recorded sense.
with determination; in a determined manner
“he clung to the past determinedly”
Definitions, synonyms and semantic relations for unshakably come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.