Not as much found in holes, surprisingly (4)
I believe the answer is:
less
'not as much' is the definition.
(similar in meaning)
'in holes surprisingly' is the wordplay.
'in' indicates a hidden word.
'LESS' can be found hidden inside 'holes surprisingly'.
'found' acts as a link.
(Other definitions for less that I've seen before include "In smaller quantity" , "more, as they say" , "So-called St James" , "Comparative of 'a little'" , "A smaller amount" .)