The most common and most likely answer to this crossword clue is the 9 letter word MEGASTORE
I've seen this crossword clue in The Times
M
E
G
A
S
T
O
R
E
More clues leading to the result MEGASTORE
- It could turn into some great outlet
- Margaret, pioneering female Conservative, and European giant in business
- Gasometer redeveloped as retail outlet
- , 2 Some great awful shop
- Massive outlet feeding biodome, gas to release
- Return last of stale crumbles a treasure found in Walmart?
- Design stage in additional shop, large one.
- Game played by a good man with some Scandinavian coins from a very large shop
- Some gas to release around outlet
Buddy explains!

The straight part
We know that "outlet" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case outlet = megastore.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 MEGASTORE mean?
MEGASTORE noun- A large supermarket or similar retail outlet; a superstore.