Manager of an outstanding stud (4)
I believe the answer is:
boss
This could be a double definition.
'manager' is the first definition.
(I've seen this in another clue)
'an outstanding stud' is the second definition.
'boss' can be an answer for 'stud' (synonyms). I'm not sure about the 'an outstanding' bit.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for boss that I've seen before include "Team manager" , "One managing" , "One who manages" , "Manager (colloq.); stud" , "Behave overbearingly" .)