Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
mind-boggling is an adjective meaning "intellectually or emotionally overwhelming". It carries one recorded sense.
intellectually or emotionally overwhelming
“a mind-boggling display”
“a mind-boggling puzzle”
Definitions, synonyms and semantic relations for mind-boggling come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.