Amaze, stun (11)

I believe the answer is:

flabbergast

This clue is a double definition.

'amaze' is the first definition.
(thesaurus)

'stun' is the second definition.
(thesaurus)

(Other definitions for flabbergast that I've seen before include "Strike dumb" , "floor" , "Surprise greatly" , "Astonish" , "Astound" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.