Coloured eye part (4)
I believe the answer is:
iris
'coloured eye part' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for iris that I've seen before include "--- Murdoch, author" , "Flag - flower - girl" , "A flower; spirit conjured in Tempest" , "Fleur-de-lis" , "Nice flower or eye part" .)