stra·​tum | \ ˈstrā-təm How to pronounce stratum (audio) , ˈstra- How to pronounce stratum (audio) \
plural strata\ ˈstrā-​tə How to pronounce strata (audio) , ˈstra-​ How to pronounce strata (audio) \

Definition of stratum

1 : a bed or layer artificially made
2a : a sheetlike mass of sedimentary rock or earth of one kind lying between beds of other kinds
b : a region of the sea or atmosphere that is analogous to a stratum of the earth
c : a layer of tissue deep stratum of the skin
d : a layer in which archaeological material (such as artifacts, skeletons, and dwelling remains) is found on excavation
3a : a part of a historical or sociological series representing a period or a stage of development
b : a socioeconomic level of society comprising persons of the same or similar status especially with regard to education or culture
4 : one of a series of layers, levels, or gradations in an ordered system strata of thought
5 : a statistical subpopulation

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Synonyms for stratum


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Is strata singular or plural?: Usage Guide

The plural strata has occasionally been used as a singular since the 18th century and is sometimes given the plural stratas. there was a strata of Paris which mere criticism of books fails to get hold of — Ezra Pound a Roman burial ground suggests stratas of corruption and decay — Connie Fletcher, Booklist Current evidence shows senses 2, 3b, and 4 so used, with sense 3b the most common. Singular strata is persistent but not frequent. Strata may someday establish itself as a singular like agenda, but that use is still not established. We should also point out that there is a derivative culinary term strata, entered separately in this dictionary, which has a singular sense, denoting a layered and baked dish whose ingredients include eggs, bread, and cheese. For the edible strata the logical and usual plural is stratas, but strata is also used as a secondary plural (as in "several ham and cheese strata"), presumably by those for whom stratas looks like an error.

Did You Know?

In geology, a stratum is a layer of rock or soil that is distinct from those above and below it. Rock and soil strata (notice the plural form) can be seen in road cuts, cliffs, quarries, riverbanks, and sand dunes, and in pieces of limestone, slate, and shale. Archaeologists digging in historical sites are careful to note the stratum where each artifact is found. Earth scientists divide the earth's atmosphere into strata, just as oceanographers divide the ocean's depths into strata. And for social scientists, a stratum is a group of people who are similar in some way, such as education, culture, or income.

Examples of stratum in a Sentence

the lower strata of society have been hit especially hard by this economic downturn the level of writing in that pop novel is several strata beneath that of serious fiction
Recent Examples on the Web To the uninitiated, his argument was technical and narrow: the stratum at Megiddo that had yielded the palace and other monumental architecture should be down-dated to the ninth century B.C., as should comparable layers at other sites. Ruth Margalit, The New Yorker, "In Search of King David’s Lost Empire," 22 June 2020 As the film world and fans mourned his passing Wednesday, sentiments came from all over the globe and all strata of celebrity. Los Angeles Times, "Appreciation: Irrfan Khan, movie star of unmatched grace, exuded emotion in the smallest of acts," 29 Apr. 2020 The shutdown promises to affect all strata of the industry, from the owners and their celebrity chefs to the waiters and waitresses, bar-backs and busboys, who effectively are facing layoffs and may be unable to pay their rent. Michael Wilson, New York Times, "‘We’re Completely Lost’: Coronavirus Hits N.Y. Restaurants," 16 Mar. 2020 This inward pull relates to her sense of memory and place: all topics are topos, terrain, their meanings leaved in geologic strata. Katy Waldman, The New Yorker, "Rebecca Solnit’s Memoir Is Much More Than a Feminist Manifesto," 11 Mar. 2020 Big, round notes resounded in all strata of her voice, seeming to flow as naturally as speech. Globe Staff,, "Andris Nelsons, Tanglewood Music Center Orchestra bring the thunder with ‘Walküre’," 29 July 2019 Menu includes spring salad, cinnamon rolls, choice of two entrees from ham, quiche or sausage and ricotta strata, choice of two quart-sized sides from creamed spinach, roasted carrots or macaroni and cheese and lemon cupcakes for dessert. Chris Sims, Indianapolis Star, "Planning Mother's Day brunch? Here are 25 restaurants with takeout deals near Indianapolis," 29 Apr. 2020 Indeed, and not coincidentally, the name of the last stage of this period is the Maastrichtian, for these are strata that originally defined it. The Economist, "Palaeontology Another ancient bird skull is another bit of avian history," 19 Mar. 2020 Research suggests that those in lower economic strata are likelier to catch the disease. New York Times, "As Coronavirus Deepens Inequality, Inequality Worsens Its Spread," 14 Mar. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'stratum.' 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 stratum

1599, in the meaning defined at sense 1

History and Etymology for stratum

New Latin, from Latin, spread, bed, from neuter of stratus, past participle of sternere to spread out — more at strew

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Time Traveler for stratum

Time Traveler

The first known use of stratum was in 1599

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Statistics for stratum

Last Updated

29 Jun 2020

Cite this Entry

“Stratum.” Dictionary, Merriam-Webster, Accessed 12 Jul. 2020.

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More Definitions for stratum


How to pronounce stratum (audio) How to pronounce stratum (audio)

English Language Learners Definition of stratum

: one of usually many layers of a substance (such as rock)
: a level of society made up of people of the same rank or position


stra·​tum | \ ˈstrā-təm How to pronounce stratum (audio) , ˈstra- \
plural strata\ -​tə \

Kids Definition of stratum

: layer entry 1 sense 1 a stratum of rock


stra·​tum | \ ˈstrāt-əm How to pronounce stratum (audio) , ˈstrat- How to pronounce stratum (audio) \
plural strata\ ˈstrāt-​ə How to pronounce strata (audio) , ˈstrat-​ How to pronounce strata (audio) \

Medical Definition of stratum

1 : a layer of tissue a deep stratum of the skin
2 : a statistical subpopulation

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