Those selling scrap gold, very small rings (7)
I believe the answer is:
vendors
'those selling' is the definition.
(people who sell things)
'scrap gold very small rings' is the wordplay.
'scrap' becomes 'end' (synonyms).
'gold' becomes 'or' ('or' is the heraldic name for gold).
'very' becomes 'v' (abbreviation).
'small' becomes 's' (abbreviation - e.g. clothes size).
'rings' means one lot of letters goes inside another (some letters are ringed or contained by others).
'v'+'s'='vs'
'end'+'or'='endor'
'endor' put into 'vs' is 'VENDORS'.
(Other definitions for vendors that I've seen before include "Property sellers" , "They sell things" , "Rev nods to Latin sellers" , "Salesmen" , "they may be getting out of property" .)