Definitions:
a flat, coloured, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the centre.

a plant with showy flowers, typically of purple or yellow, and sword-shaped leaves. irises are native to both eurasia and north america and widely cultivated as ornamentals.

(of an aperture, typically that of a lens) open or close in the manner of an iris or iris diaphragm.

the goddess of the rainbow, who acted as a messenger of the gods.