iris

Definition
(noun) plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals Definition
(noun) 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 Definition
(noun) diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening