rapt attention, admiration, or astonishment at something unexpected, strange, beautiful, etc
The children gazed in wonder at the snow
a cause of wonder astonishment or admiration; a marvel
It's a wonder he wasn't killed
(used before a noun) noted for outstanding success or achievement
a wonder drug
no/little/small wonder
it is no surprise
No wonder you're tired after staying up so late last night
work/do wonders
to have a positive effect
A good night's sleep can work wonders
[Old English wundor]