Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
stupefying is an adjective meaning "so surprisingly impressive as to stun or overwhelm". It carries 3 recorded senses.
so surprisingly impressive as to stun or overwhelm
“such an enormous response was astonishing”
“an astounding achievement”
“the amount of money required was staggering”
“suffered a staggering defeat”
“the figure inside the boucle dress was stupefying”
making physically stupid or dull or insensible
“a stupefying blow to the head”
“the stupefying effects of hemp”
Definitions, synonyms and semantic relations for stupefying come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.