We've all heard of a grocery store. It's where we go to buy groceries. Someone who owns or operates the store is called a "grocer" - which sounds pretty weird in and of itself. But, what if you wanted to buy just one item? Would you be buying a "grocery?" It seems to me if you're going grocery shopping, you ought to be able to buy a grocery.
I'd ask the people over at Safeway, but that's a "super market."