cat·​a·​ract | \ ˈka-tə-ˌrakt How to pronounce cataract (audio) \

Definition of cataract

1 [Middle English, from Middle French or Medieval Latin; Middle French catharacte, from Medieval Latin cataracta, from Latin, portcullis] : a clouding of the lens of the eye or of its surrounding transparent membrane that obstructs the passage of light
2a obsolete : waterspout
b : waterfall especially : a large one over a precipice
c : steep rapids in a river the cataracts of the Nile
d : downpour, flood cataracts of rain cataracts of information

Other Words from cataract

cataractous \ ˌka-​tə-​ˈrak-​təs How to pronounce cataract (audio) \ adjective

Synonyms for cataract


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Cataract dates to the 14th century and comes from the Latin word cataracta, meaning "portcullis." The Latin pertains to the ocular cataract, probably because it obstructs one's vision much like the portcullis's heavy iron grating obstructs passage into a fortress or castle. Cataracta has another meaning, however—"waterfall"—and that meaning gave English the water-related meanings that came in later centuries. The connection between the two Latin meanings can be seen in katarassein, the Greek source of cataracta. It means "to dash down," an action we see in both the slamming portcullis and the cascading waterfall.

Examples of cataract in a Sentence

the roaring cataract is one of the park's most majestic sights in spring the melting snows usually produce a cataract that inundates the valley
Recent Examples on the Web In any kind of cataract surgery, the eye is measured to get the correct strength of the lens, but post-operative changes in the eye can make the new lens focus light imprecisely. Dr. Keith Roach, oregonlive, 28 July 2022 Bewley had cataract surgery the day before the crash and was on the phone with a Journal Sentinel reporting intern when the crash occurred. Molly Beck, Journal Sentinel, 26 July 2022 Los Angeles Times His-and-hers cataract surgeries, but his was 20 times as much. Laura J. Nelson, Los Angeles Times, 28 June 2022 During cataract surgery, doctors only perform those tasks that require their level of experience and expertise. London Business School, Forbes, 27 June 2022 Two people who have spoken with the Pelosis since the crash said that Mr. Pelosi had had cataract surgery in the days preceding the dinner. New York Times, 22 June 2022 Tyler’s lyrics formed a cataract of consonants that worked themselves into frenzied screeches or passionate croons. Washington Post, 8 Mar. 2022 And on a third occasion, she was denied access to a specialist who my friend felt could have corrected an earlier, botched cataract surgery. Sachin H. Jain, Forbes, 12 Apr. 2022 My spouse, who is 72, had to have cataract surgery in his 60s and, until recently, had never taken multis. Dr. Keith Roach, oregonlive, 6 Apr. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cataract.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of cataract

14th century, in the meaning defined at sense 1

History and Etymology for cataract

Latin cataracta waterfall, portcullis, from Greek kataraktēs, from katarassein to dash down, from kata- + arassein to strike, dash

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The first known use of cataract was in the 14th century

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cataract bird

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Last Updated

2 Aug 2022

Cite this Entry

“Cataract.” Dictionary, Merriam-Webster, Accessed 17 Aug. 2022.

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More Definitions for cataract


cat·​a·​ract | \ ˈka-tə-ˌrakt How to pronounce cataract (audio) \

Kids Definition of cataract

1 : a clouding of the lens of the eye or of the cover around the lens that blocks the passage of light
2 : a large waterfall
3 : a sudden rush or flow like a waterfall


cat·​a·​ract | \ ˈkat-ə-ˌrakt How to pronounce cataract (audio) \

Medical Definition of cataract

: a clouding of the lens of the eye or its surrounding transparent membrane that obstructs the passage of light

More from Merriam-Webster on cataract

Nglish: Translation of cataract for Spanish Speakers

Britannica English: Translation of cataract for Arabic Speakers Encyclopedia article about cataract


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