Maybe mum or dad given monthly payment? (6)
I believe the answer is:
parent
'maybe mum' is the definition.
(mum is a type of parent)
'dad given monthly payment?' is the wordplay.
'dad' becomes 'pa' (synonyms).
'given' means one lot of letters go next to another.
'monthly payment?' becomes 'rent' (rent is often paid monthly).
'pa'+'rent'='PARENT'
'or' is the link.
(Other definitions for parent that I've seen before include "Rear" , "One raises issue" , "Mum or dad" , "What mums and dads do" , "One with offspring" .)