The most common and most likely answer to this crossword clue is the 8 letter word ASTONISH
I've seen this crossword clue in The Guardian
A
S
T
O
N
I
S
H
More clues leading to the result ASTONISH
- Stun somewhat like Bond’s DB5?
- “Villa’s other half is hotel” shock
- Perhaps Martin's partner in sports car is hard to shock
- Surprise greatly with regard to broken shin
- Shock when Villa’s first half is hard
- Shock when nonsense’s written about Northern Ireland
- Stagger, since weight is heavy at first
- Substantial weight is in wood floor
- A bit like part of Birmingham, creating surprise?
- Stagger out of university, sort of
Buddy explains!

The straight part
We know that "surprise" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case surprise = astonish.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ASTONISH mean?
ASTONISH verb- To surprise greatly.