Annoying permutation to be reordered (11)
I believe the answer is:
importunate
'annoying' is the definition.
(thesaurus)
'permutation to be reordered' is the wordplay.
'to be reordered' is an anagram indicator (I've seen 'reorder' mean this (I've seen this in other clues)).
'permutation' anagrammed gives 'IMPORTUNATE'.
(Other definitions for importunate that I've seen before include "urgent" , "Persistent, pressing" , "Annoyingly persistent" , "Demanding" .)