The majority need time for treatment (7)
I believe the answer is:
massage
'for treatment' is the definition.
(I have seen 'therapeutic treatment' mean 'massage' so perhaps 'treatment' could also mean 'massage')
'the majority need time' is the wordplay.
'the majority need' becomes 'mass' (I can't justify this - if you can you should give a lot more credence to this answer).
'time' becomes 'age' (an age is a period of time).
'mass'+'age'='MASSAGE'
Can you help me to learn more?
(Other definitions for massage that I've seen before include "Manipulate to get better results" , "Treatment by hand" , "Present favourably" , "Relaxing treatment" , "Manipulate the muscles" .)