Master of arms messing about with toe (7)
I believe the answer is:
maestro
'master' is the definition.
(I know that master can be written as maestro)
'arms messing about with toe' is the wordplay.
'messing about with' indicates an anagram.
'arms' with its letters anagrammed with 'toe' gives 'MAESTRO'.
'of' is the link.
(Other definitions for maestro that I've seen before include "Highly talented figure in a given field" , "Eminent musician" , "Eminent conductor or composer" , "Noted conductor" , "Some art (anag.)" .)