diatomaceous earth



a fine siliceous earth composed chiefly of the cell walls of diatoms: used in filtration, as an abrasive, etc.

Origin of diatomaceous earth

First recorded in 1880–85
Also called di·at·o·mite [dahy-at-uh-mahyt] /daɪˈæt əˌmaɪt/, kieselguhr.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for diatomite

Contemporary Examples of diatomite

  • The bluish pellets of diatomite soaked in hydrocyanic acid were poured through chutes.

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    My Visit To Hell

    Christopher Buckley

    January 30, 2009

Historical Examples of diatomite

British Dictionary definitions for diatomite



a soft very fine-grained whitish rock consisting of the siliceous remains of diatoms deposited in the ocean or in ponds or lakes. It is used as an absorbent, filtering medium, insulator, filler, etcSee also diatomaceous earth

diatomaceous earth


an unconsolidated form of diatomiteAlso called: kieselguhr
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

diatomite in Medicine

diatomaceous earth

[dī′ə-tə-māshəs, dī-ăt′ə-]


A powder made of the desiccated shells of diatoms, used as a filtering agent, adsorbent, and abrasive in many chemical operations.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

diatomite in Science



A fine, light-colored, friable sedimentary rock consisting mainly of the silica-rich cell walls of diatoms. Diatomite forms both in lacustrine and marine environments. It is used in industry as a filler, filtering agent, absorbent, abrasive, and insulator.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.