Chic to a fault, but disordered (7)
I believe the answer is:
chaotic
'disordered' is the definition.
(I've seen this in another clue)
'chic to a fault' is the wordplay.
'fault' indicates an anagram (a faulty spelling).
'chic'+'to'+'a'='chictoa'
'chictoa' is an anagram of 'CHAOTIC'.
'but' is the link.
(Other definitions for chaotic that I've seen before include "All over the place" , "mess" , "in random order" , "Confused, disordered" , "In complete disorder" .)