Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
disconcertingly is an adverb meaning "in a disturbing or embarrassing manner". It carries one recorded sense.
in a disturbing or embarrassing manner
“he drank some sherry, his eyes disconcertingly keen as he watched her”
Definitions, synonyms and semantic relations for disconcertingly come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.