Burden of brother in control (7)
I believe the answer is:
refrain
'burden' is the definition.
(thesaurus)
'brother in control' is the wordplay.
'brother' becomes 'fra' (title for an Italian monk).
'in' is an insertion indicator.
'control' becomes 'rein' (rein is a kind of control).
'fra' put into 'rein' is 'REFRAIN'.
'of' is the link.
(Other definitions for refrain that I've seen before include "Repeating line in a song, poem" , "Cease - repeated phrase" , "Recurring music to forbear from" , "Don't do that - it's a song" , "Chorus; desist" .)