The most common and most likely answer to this crossword clue is the 11 letter word SUPERMARKET
I've seen this crossword clue in The Daily Telegraph
S
U
P
E
R
M
A
R
K
E
T
More clues leading to the result SUPERMARKET
Buddy explains!

The straight part
We know that "shop" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shop = supermarket.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SUPERMARKET mean?
SUPERMARKET noun- A large self-service store that sells groceries and, usually, medications, household goods and/or clothing.
- A chain of such stores.
- A one-stop shop; a place offering a range of products or services.