Detective's certain to accept appeal for offence (11)
I believe the answer is:
displeasure
'offence' is the definition.
'detective's certain to accept appeal' is the wordplay.
'detective's' becomes 'dis' (Detective Inspector).
'certain' becomes 'sure' ('sure' can be a synonym of 'certain').
'to accept' means one lot of letters goes inside another.
'appeal' becomes 'plea' (plea is a kind of appeal**).
'dis'+'sure'='dissure'
'dissure' going around 'plea' is 'DISPLEASURE'.
'for' is the link.
(Other definitions for displeasure that I've seen before include "Feeling of annoyance" , "Annoyance, disapproval" .)