Give out one’s petition (5)
I believe the answer is:
issue
'give out' is the definition.
(I've seen this before)
'one's petition' is the wordplay.
'one's' becomes 'i's' (Roman numeral).
'petition' becomes 'sue' (both can mean to appeal or ask for something).
'is'+'sue'='ISSUE'
(Other definitions for issue that I've seen before include "Instalment" , "Matter of debate" , "Put out; result" , "Subject for discussion; dish out" , "Matter of dispute" .)