Greek rainbow goddess (4)
I believe the answer is:
iris
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">greek rainbow goddess</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for iris that I've seen before include "Greek goddess of the rainbow" , "plant with showy flowers" , "Circular coloured membrane in the eye" , "Pupil's place?" , "A flower; spirit conjured in Tempest" .)