Leader or chief (4)
I believe the answer is:
boss
This clue is a double definition.
'leader' is the first definition.
(I know that leader can be written as boss)
'chief' is the second definition.
(I know that chief can be written as boss)
(Other definitions for boss that I've seen before include "Domineer" , "Stud; chief" , "One managing" , "Person managing" , "Take charge of" .)