Breadcrumb Home > Dictionary > Index I iris diaphragm: Meaning and Definition of Find definitions for: i'ris di"aphragm Pronunciation: [key] — Optics, Photog. Optics,Photog. a composite diaphragm with a central aperture readily adjustable for size, used to regulate the amount of light admitted to a lens or optical system. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. irisation iris diaphragm shutter TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: variegate Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language