The man in the suit (5)
I believe the answer is:
serge
'the man' is the definition.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for serge that I've seen before include "Twilled fabric; name" , "Twilled woollen fabric" , "Durable fabric" , "Stuff" , "Material to suit" .)