iris

I. noun (plural irises; also irides) Etymology: Middle English, from Latin irid-, iris rainbow, iris plant, from Greek, rainbow, iris plant, iris of the eye — more at wire Date: 15th century 1. rainbow 2. [New Latin irid-, iris, from Greek] a. the opaque contractile diaphragm perforated by the pupil and forming the colored portion of the eye — see eye illustration b. iris diaphragm; also a similar device with a circular opening that can be varied in size 3. also plural iris [New Latin Irid-, Iris, genus name, from Latin] any of a large genus (Iris of the family Iridaceae, the iris family) of perennial herbaceous plants with linear usually basal leaves and large showy flowers II. transitive verb Date: 1816 to make iridescent