plank·​ton | \ˈplaŋ(k)-tən, -ˌtän\

Definition of plankton 

: the passively floating or weakly swimming usually minute animal and plant life of a body of water

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Other Words from plankton

planktonic \ plaŋ(k)-​ˈtä-​nik \ adjective

Examples of plankton in a Sentence

fish that feed mainly on plankton

Recent Examples on the Web

The sharks thrive on these tiny floating critters, chowing down by swimming close to the surface of the water, mouths agape, filtering the plankton in their specialized gills. Jason Daley, Smithsonian, "Massive Gathering of Mysterious Basking Sharks Found in Aerial Photos," 13 Apr. 2018 From microscopic plankton to sea horses, anemones and sharks, little survives inside the 30- to 100-foot radius of an explosion. Aurora Almendral, New York Times, "In the Philippines, Dynamite Fishing Decimates Entire Ocean Food Chains," 15 June 2018 Young visitors can test water quality and trawl for plankton with the Billion Oyster Project, learn angling with I Fish NY, make sea creature masks and other crafts, and enjoy live music and theater. Laurel Graeber, New York Times, "9 Things to Do With Your Kids in N.Y.C. This Weekend," 12 July 2018 Hungry microbes The measurements did find plenty of ancient methane at the bottom, although there was also young methane produced by the microbial breakdown of dead plankton (another source is atmospheric methane that mixes into the water). Scott K. Johnson, Ars Technica, "Submerged permafrost releasing methane, but not into the atmosphere," 24 Jan. 2018 Materials with Green Art Workshop Make your own insects, plankton, microbes, and other tiny beings with Green Art Workshop., "Kids listings," 12 July 2018 The pigments, which come from algae and plankton, imbue his slabs and chunks of wood with an otherworldly light best viewed in the dark. Cate Mcquaid,, "Seeing the heavens in a cut of wood," 11 July 2018 The nontraditional farming method involves stocking bodies of water with paddlefish that feed on natural populations of plankton and that are harvested for both their meat and eggs. Bailey Loosemore, The Courier-Journal, "Kentucky is swimming with potential to take over the US caviar market," 28 June 2018 Deep ocean blues On moonless nights in some parts of the world, the surface of the sea shimmers with blue blooms of bioluminescent plankton. Katherine J. Wu, Smithsonian, "Why Bioluminescence Evolved to Be Red Light, and Blue," 26 June 2018

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

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First Known Use of plankton

1889, in the meaning defined above

History and Etymology for plankton

German, from Greek, neuter of planktos drifting, from plazesthai to wander, drift, middle voice of plazein to drive astray; akin to Latin plangere to strike — more at plaint

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Statistics for plankton

Last Updated

14 Nov 2018

Look-up Popularity

Time Traveler for plankton

The first known use of plankton was in 1889

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More Definitions for plankton



English Language Learners Definition of plankton

: the very small animal and plant life in an ocean, lake, etc.


plank·​ton | \ˈplaŋk-tən \

Kids Definition of plankton

: the tiny floating plants and animals of a body of water

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Comments on plankton

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