Smart shop fails (4)
I believe the answer is:
posh
'smart' is the definition.
(both can mean fancy or formal)
'shop fails' is the wordplay.
'fails' is an anagram indicator (I've seen 'failing' mean this).
'shop' with letters rearranged gives 'POSH'.
(Other definitions for posh that I've seen before include "Smart, fashionable" , "Peterborough" , "This 13 [SPICE]" , "Upper-class - elegant" , "Stylish (informal)" .)