Woman from Emerald Isle shuns husband (4)
I believe the answer is:
'woman' is the definition.
'emerald isle shuns husband' is the wordplay.
I cannot really understand how this works, but
'isle' could be 'is' (geographical abbreviation) and 'is' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'from' acts as a link.
Can you help me to learn more?
(Other definitions for iris that I've seen before include "Fleur-de-lys" , "Camera diaphragm" , "Flag,flower and part of the eye" , "Goddess of the rainbow in the eye" , "Nice flower or eye part" .)