# iris

/ˈaɪɹəs/ (US) · /ˈaɪɹɪs/ (UK)

Source: https://englishreference.com/word/iris
Updated: 2026-08-15

## Senses

### 1. part of the eye

noun · CEFR B2

the colored part of your eye around the black pupil.

For teachers: the pigmented, contractile membrane of the eye, situated between the cornea and lens, which regulates the amount of light reaching the retina.

- The doctor looked closely at the patient's iris to check for any unusual spots.
- The biometric scanner identifies individuals by mapping the unique patterns and textures found within the human iris.

### 2. a flower

noun · CEFR B2

a tall plant with large, colorful flowers that usually have three petals pointing up and three hanging down.

For teachers: any plant of the genus Iris, characterized by showy flowers and sword-shaped leaves.

- She planted purple irises along the edge of the garden path.
- The botanical garden features a diverse collection of bearded irises, which bloom in a spectacular array of colors during the late spring.

### 3. camera part

noun · CEFR C1 · Technical

the part of a camera lens that opens and closes to control how much light gets in.

For teachers: an adjustable diaphragm consisting of thin overlapping plates, used to control the aperture of a lens.

- The photographer adjusted the iris to make the background look blurry.
- By narrowing the iris of the lens, the cinematographer was able to maintain a deep focus across the entire landscape.

### 4. a rainbow

noun · CEFR C2 · Literary

a rainbow or a bright display of many colors.

For teachers: a rainbow or an iridescent appearance resembling a rainbow.

- An iris of light appeared in the mist above the waterfall.
- The poet described the morning dew as a thousand tiny irises scattered across the meadow grass.

### 5. to open or close

verb · CEFR C2 · Technical · Literary

to open or close slowly like the part of an eye or a camera lens.

For teachers: to expand or contract in a manner resembling the movement of an ocular or mechanical iris.

- The mechanical door irised open to let the crew inside.
- The stage lights slowly irised down, focusing a single, sharp beam on the lead actor as the scene concluded.

## Examples

- Her iris is a striking shade of deep green.
- The doctor used a bright light to check how quickly the patient's iris reacted to the change.
- In low light conditions, the muscles of the iris relax to dilate the pupil, allowing the maximum amount of visual information to reach the sensory cells of the retina.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.