a descent of water over a steep surface; a waterfall, especially one of considerable size.
any furious rush or downpour of water; deluge.
  1. an abnormality of the eye, characterized by opacity of the lens.
  2. the opaque area.

Origin of cataract

1350–1400; Middle English cataracte < Latin catar(r)acta < Greek katarráktēs waterfall, floodgate, portcullis (noun), downrushing (adj.), akin to katarássein to dash down, equivalent to kat- cata- + arássein to smite
Related formscat·a·rac·tal, cat·a·rac·tous, adjectivecat·a·ract·ed, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for cataract

flood, torrent, deluge, rapids

Examples from the Web for cataract

Historical Examples of cataract

  • That river has a cataract or fall, at about an hundred and fifty leagues from its confluence.

    The History of Louisiana

    Le Page Du Pratz

  • A lake had burst on its summit, and the cataract became a falling Ocean.

    Vivian Grey

    Earl of Beaconsfield, Benjamin Disraeli

  • You must be in a hurry to do it, too, coming downstairs like a cataract.

    The Christian

    Hall Caine

  • Lady O'Moy was in an emotional maelstrom that swept her towards a cataract.

    The Snare

    Rafael Sabatini

  • I crossed it dry-shod at day-break, and now, it is a cataract.

    The O'Donoghue

    Charles James Lever

British Dictionary definitions for cataract



a large waterfall or rapids
a deluge; downpour
  1. partial or total opacity of the crystalline lens of the eye
  2. the opaque area

Word Origin for cataract

C15: from Latin catarracta, from Greek katarrhaktēs, from katarassein to dash down, from arassein to strike
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for cataract

early 15c., "a waterfall, floodgate," from Latin cataracta "waterfall," from Greek katarhaktes "waterfall, broken water; a kind of portcullis," noun use of an adjective compound meaning "swooping, down-rushing," from kata "down" (see cata-). The second element is traced either to arhattein "to strike hard" (in which case the compound is kat-arrhattein), or to rhattein "to dash, break."

Its alternative sense in Latin of "portcullis" probably was passed through French to form the English meaning "eye disease" (early 15c.), on the notion of "obstruction" (to eyesight).

Online Etymology Dictionary, © 2010 Douglas Harper

cataract in Medicine




Opacity of the lens or capsule of the eye, causing impairment of vision or blindness.
Related formscat′a•ractous (-răktəs) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

cataract in Science



An opacity of the lens of the eye or the membrane that covers it, causing impairment of vision or blindness.
A waterfall in which a large volume of water flows over a steep precipice.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

cataract in Culture



A loss in the transparency of the lens of the eye, which reduces a person's ability to see. The condition can be treated by surgically removing the lens and replacing it with an artificial one, or with corrective eyeglasses or contact lenses.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.