Messy site cleaned to accommodate small shop (12)
I believe the answer is:
delicatessen
'shop' is the definition.
(delicatessen is a kind of shop)
'messy site cleaned to accommodate small' is the wordplay.
'messy' indicates anagramming the letters.
'to accommodate' means one lot of letters goes inside another.
'small' becomes 's' (abbreviation - e.g. clothes size).
'site'+'cleaned'='sitecleaned'
'sitecleaned' is an anagram of 'delicatesen'.
'delicatesen' going around 's' is 'DELICATESSEN'.
(Other definitions for delicatessen that I've seen before include "Shop selling specialist foods" , "Fine foods shop" , "Shop selling unusual or foreign prepared food" , "Shop selling exotic prepared foods" , "Specialised food shop" .)