iris diaphragm

noun

: an adjustable diaphragm of thin opaque plates that can be turned by a ring so as to change the diameter of a central opening usually to regulate the aperture of a lens

Word History

First Known Use

1867, in the meaning defined above

Time Traveler

The first known use of iris diaphragm was in 1867

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Cite this Entry

Style

“Iris diaphragm.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/iris%20diaphragm. Accessed 20 Mar. 2023.

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Kids Definition

iris diaphragm

noun

: an adjustable diaphragm of thin plates used for changing the diameter of a central opening to control the amount of light passing (as into a microscope or camera)

Medical Definition

iris diaphragm

noun

: an adjustable diaphragm of thin opaque plates that can be turned by a ring so as to change the diameter of a central opening usually to regulate the aperture of a lens (as in a microscope)