By whose industry maybe Mark was won round (7)
I believe the answer is:
workman
'round' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'by whose industry maybe mark was won' is the wordplay.
I cannot really see how this works, but
an anagram of 'mark' is 'rkma' which is located in the answer.
'won' could be 'w' (I've seen this in other clues) and 'w' is present in the answer.
The remaining letters 'on' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for workman that I've seen before include "Artisan" , "Manual labourer" , "employee" .)