Gold foreign coin found by ring in river (7)
I believe the answer is:
orinoco
'river' is the definition.
(Orinoco River is an example)
'gold foreign coin found by ring' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'foreign' indicates anagramming the letters (foreign order of the letters).
'found by' is a charade indicator (letters next to each other).
'ring' becomes 'o'.
'coin' is an anagram of 'inoc'.
'or'+'inoc'+'o'='ORINOCO'
'in' acts as a link.
(Other definitions for orinoco that I've seen before include "River, rising in Venezuela, forming part of its border with Colombia and flowing into the Atlantic" , "South-American river" , "Colombia/Venezuela river" , "Womble; S. Amer. river" , "South American river - lazy Womble" .)