Crushed apricot's not right with a pudding (7)
I believe the answer is:
tapioca
'pudding' is the definition.
(tapioca pudding is a kind of pudding)
'crushed apricot's not right with a' is the wordplay.
'crushed' indicates anagramming the letters.
'not' is a deletion indicator.
'right' becomes 'r' (common abbreviation).
'with' indicates putting letters inside.
'apricot' with 'r' taken out is 'apicot'.
'apicot' is an anagram of 'tpioca'.
'tpioca' placed around 'a' is 'TAPIOCA'.
(Other definitions for tapioca that I've seen before include "I act OAP (anag) - edible substance made from cassava" , "Starchy pudding" , "Pudding from the cassava root" , "it thickens" , "course" .)