Character in Greek apparel (5)
I believe the answer is:
kappa
'character' is the definition.
(I know that kappa is a type of letter)
'in greek apparel' is the wordplay.
'in' indicates the answer is hidden within the clue.
'KAPPA' is hidden in the letters of 'greek apparel'.
(Other definitions for kappa that I've seen before include "10th Greek letter" , "Letter before lambda" , "letter from abroad" , "Greek K" , "Greek character" .)