Astute, missing nothing, considering disorder (10)
I believe the answer is:
discerning
'astute' is the definition.
(thesaurus)
'missing nothing considering disorder' is the wordplay.
'missing' is a deletion indicator.
'nothing' becomes 'o' (looks like zero - 0).
'disorder' is an anagram indicator (I've seen 'diseased' mean this (I've seen this in other clues)).
'considering' with 'o' removed is 'cnsidering'.
'cnsidering' with letters rearranged gives 'DISCERNING'.
(Other definitions for discerning that I've seen before include "clever" , "Making out" , "Showing good judgement" , "Particular" , "Unobtrusively perceptive" .)