In favour of calling - something to make one angry (11)
I believe the answer is:
provocation
'something to make one angry' is the definition.
I can't judge whether this definition defines the answer.
'in favour of calling' is the wordplay.
'in favour of' becomes 'pro' (being pro a particular cause).
'calling' becomes 'vocation' (a vocation is a calling).
'pro'+'vocation'='PROVOCATION'
Can you help me to learn more?
(Other definitions for provocation that I've seen before include "Cause" , "Annoying action" .)