Prone to prosecute, hiding fix (6)
I believe the answer is:
supine
'prone' is the definition.
(thesaurus)
'prosecute hiding fix' is the wordplay.
'prosecute' becomes 'sue' (I've seen this before).
'hiding' means one lot of letters goes inside another.
'fix' becomes 'pin' (to pin is to fix in place).
'sue' going around 'pin' is 'SUPINE'.
'to' acts as a link.
(Other definitions for supine that I've seen before include "Slow in acting" , "Recumbent" , "Inert; on one's back" , "Flat on one's back" , "looking up" .)