Loaf, being the boss (4)
I believe the answer is:
head
I believe this clue is a double definition.
'loaf' is the first definition.
(I've seen this in other clues)
'being the boss' is the second definition.
(I've seen this before)
(Other definitions for head that I've seen before include "Skull" , "Leader; water pressure" , "Chief; part of body" , "Edible part of cabbage" , "Chief; promontory" .)