One who makes a profit from hangings, of course (6)
I believe the answer is:
draper
'one who makes a profit from hangings of course' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'one who makes a' is the wordplay.
I cannot quite see how this works, but
'one' could be 'a' (a thing is one thing) and 'a' is present in the answer.
'who' could be 'dr' (from TV series Doctor Who) and 'dr' is present in the answer.
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for draper that I've seen before include "Dealer in cloth and clothing" , "He sells fabrics" , "Retailer of cloth" , "Seller of cloth" , "Retailer of fabrics" .)