Of a nature to astound; astonishing; amazing; as, an astounding force, statement, or fact
If something is astounding, you are shocked or amazed that it could exist or happen. The results are quite astounding. = amazing, astonishing + astoundingly astound·ing·ly astoundingly blue eyes. so surprising that it is almost impossible to believe = astonishing
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"
If something astounds you, you are very surprised by it. He used to astound his friends with feats of physical endurance. = astonish. to make someone very surprised or shocked = astonish (Probably from the past participle of astone; ASTONISH)