Detective’s appeal guaranteed offence (11)
I believe the answer is:
displeasure
'offence' is the definition.
'detective's appeal guaranteed' is the wordplay.
'detective's' becomes 'di's' (Detective Inspector).
'appeal' becomes 'plea' (plea is a kind of appeal).
'guaranteed' becomes 'sure' (I've seen this in other clues).
'dis'+'plea'+'sure'='DISPLEASURE'
(Other definitions for displeasure that I've seen before include "Annoyance, disapproval" , "Feeling of annoyance" .)