Characteristic trait shaped Scottish island (9)
I believe the answer is:
attribute
'characteristic' is the definition.
(I've seen this before)
'trait shaped scottish island' is the wordplay.
'shaped' is an anagram indicator.
'scottish island' becomes 'bute' (I've seen this in other clues).
'trait' with letters rearranged gives 'attri'.
'attri'+'bute'='ATTRIBUTE'
(Other definitions for attribute that I've seen before include "Impute - quality" , "Quality representative of person" , "Ascribe, impute" , "A special characteristic" , "Point" .)