Ongelooflijk!

Hmmm - this warrants a post as babel translates Ongelooflijk as "Incredibly". Here babel actually does something that many dictionaries also do; they mis-translate the word. "Ongelooflijk" is from the root noun geloof: belief. "On~" is similiar to the English prefix "Un~". "Lijk" as a suffux often (but not always) means ~ly - for example, friendly is vriendelijk or vriendschappelijk.

So - in summation Ongelooflijk correctly translates to unbelievably. Unbelievable is Niet Gelooflijk. Incredible, as an exclamation, is more akin to "Geweldig" - the adjective "terrific"

There end-eth my Nederlands showing off for the day - and also endeth the pain of typing with a fracture :-)