Store fat eating every brand (11)
I believe the answer is:
supermarket
'store' is the definition.
(I've seen this before)
'fat eating every brand' is the wordplay.
'fat' becomes 'suet' (suet is a kind of fat).
'eating' is an insertion indicator.
'every' becomes 'per' (I've seen this in other clues).
'brand' becomes 'mark' (synonyms).
'per'+'mark'='permark'
'suet' enclosing 'permark' is 'SUPERMARKET'.
(Other definitions for supermarket that I've seen before include "Large shop" , "Large store selling food and household supplies" , "Large retail outlet" , "Grocery store" .)