Boys without power or patron (7)
I believe the answer is:
sponsor
'patron' is the definition.
(I know that patron can be written as sponsor)
'boys without power or' is the wordplay.
'boys' becomes 'sons' ('son' can be a synonym of 'boy').
'without' is an insertion indicator ('without' can be similar in meaning to 'outside').
'power' becomes 'p' (symbol in physics).
'sons' placed around 'p' is 'spons'.
'spons'+'or'='SPONSOR'
(Other definitions for sponsor that I've seen before include "One financially supporting an activity" , "A godfather or patron" , "Back financially" , "One funding an event" , "Financial backer" .)