Public watched, astonished (4-4)

I believe the answer is:

open-eyed

'astonished' is the definition.
(I've seen this before)

'public watched' is the wordplay.
'public' becomes 'open' (similar in meaning).
'watched' becomes 'eyed' (I've seen this before).
'open'+'eyed'='OPEN-EYED'

(Other definitions for open-eyed that I've seen before include "Forming an encrusted mass" , "Astonished; fully aware" , "Surprised - aware" , "Astonished - watchful" .)

I've seen this clue in The Times.

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