21 across
Turning
left,
notices
a
superstore
(4)
Turning left, notices a superstore (4)
hints
0
checks
0
hints
The definition is at the end of the clue.
How the clue works
The definition is superstore, referring to the supermarket chain ASDA. Taking "notices" (ADS) plus "a" (A) gives ADSA, and the reversal indicator "Turning" reverses it to ASDA.