Chicken reportedly caused offence (4)
I believe the answer is:
foul
'caused offence' is the definition.
The answer and definition are different parts of speech. However, adjectives and past participle verbs occasionally mean the same thing.
'chicken reportedly' is the wordplay.
'chicken' becomes 'fowl' (chicken is a type of fowl).
'reportedly' shows a homophone (sound like).
'fowl' sounds like 'FOUL'.
Can you help me to learn more?
(Other definitions for foul that I've seen before include "Abhorrent" , "Having offensive smell or taste" , "Obnoxious" , "Putrid" , "Loathsome - tackle breaking game rules" .)