adj

1. shocking with surprise and consternation

e.g. the stupefying impact of the tragedy

2. so surprisingly impressive as to stun or overwhelm

e.g. 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

Synonym: astonishingastoundingstaggering

3. making physically stupid or dull or insensible

e.g. a stupefying blow to the head
the stupefying effects of hemp