Supermarket said to be getting bigger (6)
I believe the answer is:
'supermarket' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for grocer that I've seen before include "Market trader" , "Retail merchant" , "Dealer in foodstuffs and household goods" , "Provisions purveyor" , "Seller of food and household supplies" .)