Standard average container for small cheese (8)
I believe the answer is:
parmesan
'cheese' is the definition.
(I know that Parmesan is a type of cheese)
'standard average container for small' is the wordplay.
'standard' becomes 'par' (standard of play in golf).
'average' becomes 'mean' (type of average).
'container for' indicates putting letters inside.
'small' becomes 's' (abbreviation - e.g. clothes size).
'mean' enclosing 's' is 'mesan'.
'par'+'mesan'='PARMESAN'
(Other definitions for parmesan that I've seen before include "Hard dry Italian cheese" , "Hard dry cheese, often grated" , "Cheese for grating" , "Pam earns this cheese" , "Italian cheese, often grated" .)