New store includes British sweet (6)
I believe the answer is:
sorbet
'sweet' is the definition.
(sorbet is a kind of sweet)
'new store includes british' is the wordplay.
'new' indicates anagramming the letters.
'includes' is an insertion indicator.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'store' is an anagram of 'soret'.
'soret' enclosing 'b' is 'SORBET'.
(Other definitions for sorbet that I've seen before include "Frozen dessert" , "Fruit water-ice" , "Fruit juice and water ice" , "Icy dessert" , "Sweet" .)