Sort of farm boss (4)
I believe the answer is:
stud
I believe this clue is a double definition.
'sort of farm' is the first definition.
'boss' is the second definition.
('stud' can be a synonym of 'boss')
(Other definitions for stud that I've seen before include "collection of cars" , "Knob; fastener; boss" , "Boss; shirt fastener" , "Gripper under a boot" , "Randy young male" .)