Some work site supervisors (7)
I believe the answer is:
foremen
'some work site supervisors' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for foremen that I've seen before include "Persons in charge" , "Resembling a bird" , "Gangers, supervisors" , "They supervise other workers" , "Workers' leaders" .)