### Clue: Chain large article edged with diamonds (7)
### Answer: ICELAND 
 ### Explanation: Definition: Chain
 [ L(abbrev. for "large") + AN(an article in grammar) ] **contained in**(edged with) [ ICE(slang for the precious stones, diamonds) + D(abbrev. for the diamonds suit in a deck of playing cards ].
Defn: … of supermarkets in the UK.