Mother's wise to have physiotherapy (7)
I believe the answer is:
massage
'have physiotherapy' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'mother's wise' is the wordplay.
'mother's' becomes 'ma's' (ma can mean mother).
'wise' becomes 'sage' (similar in meaning).
'mas'+'sage'='MASSAGE'
'to' is the link.
Can you help me to learn more?
(Other definitions for massage that I've seen before include "Manipulation of the muscles" , "therapeutic treatment" , "Present favourably" , "Knead" , "Manipulate to get better results" .)