Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
proverbially is an adverb meaning "in the manner of something that has become a byword". It carries one recorded sense.
in the manner of something that has become a byword
“this proverbially bitter plant, wormwood”
Definitions, synonyms and semantic relations for proverbially come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.