IPA: /bɪˈwɪldərɪŋli/
KK: /bɪˈwɪldərɪŋli/
In a way that causes confusion or puzzlement.
The instructions were written so bewilderingly that no one could understand them.
Bewilderingly → It is formed from "be-" (meaning to cause to be) and "wilder" (from Old English "wildor", meaning wild or to lead astray) combined with the suffix "-ingly" (meaning in a manner). The word "bewilderingly" means in a manner that causes confusion or leads one astray.
Think of being 'caused to be' ('be-') 'led astray' ('wilder') — that's why bewilderingly means something that confuses you.