"Bewilder" is already a complete word, meaning to confuse or perplex. It's formed from the Old English words "be" (meaning "by" or "completely") and "wilder" (meaning "to mislead" or "to cause to lose one's way").
If you're looking to convey a related meaning, you could use words like:
* Disorient: To make someone lose their sense of direction or awareness.
* Confuse: To make someone unable to think clearly or understand something.
* Perplex: To make someone puzzled or uncertain.
* Mystify: To make something seem mysterious or difficult to understand.