Definition of diatom in English:

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Pronunciation: /ˈdīəˌtäm/


A single-celled alga that has a cell wall of silica. Many kinds are planktonic, and extensive fossil deposits have been found.
  • Class Bacillariophyceae, division Chromophycota or Heterokontophyta (or phylum Bacillariophyta, kingdom Protista).
Example sentences
  • From single-celled algae called diatoms to the story of a man who plants acorns, IDFuel reminds us that inspiration for design is all around us.
  • The slime molds are now known to be a mixture of three or four unrelated groups, and the oomycetes are now classified in the Chromista, with the diatoms and brown algae.
  • Algae, diatoms, dinoflagellates, and photosynthetic bacteria all belong to this group of organisms.



Pronunciation: /ˌdīədəˈmāSHəs/
Example sentences
  • Although diatoms are universal in fresh and sea water, they achieve greater importance in high-latitude oceanic areas, as well as in some continental margin basins where they form diatomaceous ooze.
  • Massive, bioturbated terrigenous silty clay and diatomaceous mud dominate sedimentation in the distal ice-shelf environment.
  • ‘The bottom appeared light and clear, a waste of firm diatomaceous [algae-skeleton] ooze,’ said Piccard.


Mid 19th century: from modern Latin Diatoma (genus name), from Greek diatomos 'cut in two', from diatemnein 'to cut through'.

For editors and proofreaders

Syllabification: di·a·tom

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