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noun, stra·tum \ˈstrā-təm, ˈstra-\

Simple 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

Source: Merriam-Webster's Learner's Dictionary

Full Definition of stratum

plural strata play \ˈstrā-tə, ˈstra-\

  1. 1 :  a bed or layer artificially made

  2. 2a :  a sheetlike mass of sedimentary rock or earth of one kind lying between beds of other kindsb :  a region of the sea or atmosphere that is analogous to a stratum of the earthc :  a layer of tissue <deep stratum of the skin>d :  a layer in which archaeological material (as artifacts, skeletons, and dwelling remains) is found on excavation

  3. 3a :  a part of a historical or sociological series representing a period or a stage of developmentb :  a socioeconomic level of society comprising persons of the same or similar status especially with regard to education or culture

  4. 4 :  one of a series of layers, levels, or gradations in an ordered system <strata of thought>

  5. 5 :  a statistical subpopulation

Usage Discussion of stratum

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 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.

Examples of stratum in a sentence

  1. <the lower strata of society have been hit especially hard by this economic downturn>

  2. <the level of writing in that pop novel is several strata beneath that of serious fiction>

Origin of stratum

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

First Known Use: 1599

Other Archaeology Terms

STRATUM Defined for Kids


noun stra·tum \ˈstrā-təm, ˈstra-\

Definition of stratum for Students

plural strata \-tə\

  1. :  1layer 1 <a stratum of rock>

Medical Dictionary


play play
noun stra·tum \ˈstrāt-əm, ˈstrat-\

Medical Definition of stratum

plural strata \ˈstrāt-ə, ˈstrat-\play play

  1. 1:  a layer of tissue <a deep stratum of the skin>

  2. 2:  a statistical subpopulation

Seen and Heard

What made you want to look up stratum? Please tell us where you read or heard it (including the quote, if possible).


to dishevel or rumple

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