Dad has a regular payment for mum, maybe (6)
I believe the answer is:
parent
'for mum maybe' is the definition.
(mum is a type of parent)
'dad has a regular payment' is the wordplay.
'dad' becomes 'pa' (both can mean one's father).
'has' says to put letters next to each other.
'a regular payment' becomes 'rent' (rent is a kind of regular payment).
'pa'+'rent'='PARENT'
(Other definitions for parent that I've seen before include "One raises issue" , "E.g. father" , "One with children" , "Mother or father or what they do" , "Immediate ancestor" .)