Fleur-de-lys (4)
I believe the answer is:
iris
'fleur-de-lys' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for iris that I've seen before include "Flag,flower and part of the eye" , "Part of the eye, usually brown or blue" , "Flag - surrounding pupil" , "Bright flower or eye part" , "Flowers in the eye?" .)