Newspaper boy from Wales is unmarried (5)
I believe the answer is:
organ
'newspaper' is the definition.
(thesaurus)
'boy from wales is unmarried' is the wordplay.
I cannot quite understand how this works, but
'boy' could be 'gan' and 'gan' is found within the answer.
The remaining letters 'or' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for organ that I've seen before include "Part with special function" , "Agency" , "Eg, heart, liver" , "Air-powered instrument" , "music producer" .)