Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
dumfounding is an adjective meaning "bewildering or striking dumb with wonder". It carries one recorded sense.
bewildering or striking dumb with wonder
Definitions, synonyms and semantic relations for dumfounding come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.