Particular case with pile for sorting (8)
I believe the answer is:
especial
'particular' is the definition.
(I know that particular can be written as especial)
'case with pile for sorting' is the wordplay.
'with' means one lot of letters go next to another.
'for sorting' indicates an anagram (letters sorted into a new order).
'case' after 'pile' is 'pilecase'.
'pilecase' is an anagram of 'ESPECIAL'.
(Other definitions for especial that I've seen before include "Spice ale wrongly and be particular" , "Over and above what is usually expected" , "Exclusive" , "Notable; for one person or thing only" , "Exceptional" .)