iris in WordNet English dictionary

1. plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals
   iris  flag  fleur-de-lis  sword lily 
   
2. diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening
   iris  iris diaphragm 
   
3. muscular diaphragm that controls the size of the pupil which in turn controls the amount of light that enters the eye; it forms the colored portion of the eye
   iris