Definition of Astounding

Adjective: astounding u'stawn-ding

Bewildering or striking dumb with wonder
"These sciences revealed not only the astounding largeness of the universe but also the dumbfounding smallness of human beings";
- dumbfounding, dumfounding
So surprisingly impressive as to stun or overwhelm
"an astounding achievement";
- astonishing, staggering, stupefying

Verb: astound u'stawnd

Fill with wonder or astonishment; greatly surprise
"Your ability to speak six languages astounds me!";
- amaze, astonish