definition of
iris

[1] #1 iris n. [flag, fleur-de-lis, sword lily] plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals. wn

[2] #2 iris n. 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. wn

[3] #3 iris n. [iris diaphragm] diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening. wn