What is prefix for surprising?

There isn't a single, universally accepted prefix for "surprising." However, there are several options you could use depending on the specific nuance you want to convey:

General surprise:

* Un-: This prefix emphasizes the unexpectedness of something, as in "unbelievable" or "unforeseen."

* Extra-: This prefix implies something exceeding expectations, as in "extraordinary" or "extravagant."

* Aston-: This prefix suggests a strong sense of wonder or amazement, as in "astonishing" or "astounding."

Negative surprise:

* Dis-: This prefix suggests something unexpected and unwelcome, as in "disappointing" or "disconcerting."

* Un-: This prefix can also imply a negative surprise, as in "unfortunate" or "unwanted."

Positive surprise:

* Delight-: This prefix emphasizes a pleasant surprise, as in "delightful" or "delighted."

* Wonder-: This prefix suggests amazement and wonder, as in "wonderful" or "wondrous."

Ultimately, the best prefix to use will depend on the specific context and the feeling you want to evoke.