Loose coat used for sweeping (7)
I believe the answer is:
overall
'sweeping' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for overall that I've seen before include "Protective coat painters put on" , "Protective clothing" , "Including everything" , "Protective cover for worker" , "sweeping?" .)