Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
lamentably is an adverb meaning "in an unfortunate or deplorable manner". It carries one recorded sense.
in an unfortunate or deplorable manner
“he was sadly neglected”
“it was woefully inadequate”
Definitions, synonyms and semantic relations for lamentably come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.