Definition

1. Noun:
   • A colored part of the eye: The iris is the circular, colored membrane behind the cornea of the eye. It surrounds the pupil and controls its size, regulating the amount of light entering the eye.
   • A type of flowering plant: An iris is a plant with long, sword-shaped leaves and showy flowers, typically with three upright petals and three drooping sepals.
   • A diaphragm with an adjustable opening: In technical contexts, an iris is a thin, overlapping diaphragm with a central opening of variable diameter, used in devices like cameras.

Usage Examples

• Noun (Eye):
  • The color of her iris is a striking shade of green.
  • The doctor examined the patient's iris for signs of disease.
• Noun (Plant):
  • She planted purple irises along the garden path.
  • The iris is the state flower of Tennessee.
• Noun (Device):
  • The camera's iris adjusts automatically to control the light.

Advanced Usage

• "Iris scanner": A biometric security device that identifies individuals by analyzing the unique patterns of their irises.
  • The high-security facility uses an iris scanner for access control.

Variants and Related Words

• Iridology (n): The study of the iris of the eye, especially as associated with disease.
• Iridectomy (n): A surgical procedure to remove part of the iris.
• Irised (adj): Having colors like those of the iris or a rainbow; iridescent.

Synonyms

• For the eye part: (None are perfect anatomical synonyms)
• For the plant: Flag, fleur-de-lis.
• For the diaphragm: Aperture stop, diaphragm.

Related Phrases

• "Iris out" (Cinematography): A transition effect where the image closes to a black circle, mimicking the closing of an iris diaphragm.
  • The old film ended with an iris out to black.

Related Idioms

• (No common idioms are directly based on the word "iris" itself.)

Noun

1. diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening
2. 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
3. plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals