Traditionally black-coated worker (5)
I believe the answer is:
sweep
'worker' is the definition.
(sweep is a kind of worker)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for sweep that I've seen before include "gambling event" , "Use a brush" , "Clean the floor" , "Cleaner of chimneys" , "Windmill sail" .)