Refuse in yard below study (4)
I believe the answer is:
deny
'refuse' is the definition.
(I've seen this before)
'yard below study' is the wordplay.
'yard' becomes 'y'.
'below' means one lot of letters go next to another.
'study' becomes 'den' (I've seen this before).
'y' after 'den' is 'DENY'.
'in' is the link.
(Other definitions for deny that I've seen before include "Refuse to acknowledge" , "Disclaim" , "Declare untrue" , "Negate" , "Reject as false" .)