stratum

[strey-tuh m, strat-uh m]

See more synonyms for stratum on Thesaurus.com

noun, plural stra·ta

[strey-tuh, strat-uh] /ˈstreɪ tə, ˈstræt ə/, stra·tums.

a layer of material, naturally or artificially formed, often one of a number of parallel layers one upon another: a stratum of ancient foundations.
one of a number of portions or divisions likened to layers or levels: an allegory with many strata of meaning.
Geology. a single bed of sedimentary rock, generally consisting of one kind of matter representing continuous deposition.

Biology. a layer of tissue; lamella.
Ecology. (in a plant community) a layer of vegetation, usually of the same or similar height.
a layer of the ocean or the atmosphere distinguished by natural or arbitrary limits.
Sociology. a level or grade of a people or population with reference to social position, education, etc.: the lowest stratum of society.
Linguistics. (in stratificational grammar) a major subdivision of linguistic structure.Compare level(def 17).

Origin of stratum

1590–1600; < Latin strātum literally, a cover, noun use of neuter of strātus, past participle of sternere to spread, strew, equivalent to strā- variant stem + -tus past participle suffix

Related formsstra·tous, adjective

Usage note

Strata, historically the plural of stratum, is occasionally used as a singular: The lowest economic strata consists of the permanently unemployable. Less frequently, a plural stratas occurs: Several stratas of settlement can be seen in the excavation. At present, these uses are not well established, and they are condemned in usage guides. Strata may eventually become part of a group of borrowed plurals that are now used as singulars in English, such as agenda and candelabra, but it is not yet in that category. See also agenda, criterion, media, phenomenon.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for stratum

lamina, sheet, level, grade, stratification, gradation, thickness, lode, bed, seam, vein

Examples from the Web for stratum

Contemporary Examples of stratum

But their young deputies and ministerial director generals tended to be from this recently-returned, Western-educated stratum.
A Ray of Light in Islamist Gloom
Benny Morris
July 17, 2012

Historical Examples of stratum

The other stratum of McClellanism (p. 191) is composed of intriguers.
Diary from November 12, 1862, to October 18, 1863
Adam Gurowski
The "blue lead" is a stratum of blue clay very rich in gold.
Hittel on Gold Mines and Mining
John S. Hittell
In this genus the stratum of the pores is not easily separated from the cap.
The Mushroom, Edible and Otherwise
M. E. Hard
Nobody but Alston, in their stratum at least, had come in person.
The Prisoner
Alice Brown
On top of each one is a stratum of sandstone or dark-gray shale.
Diggers in the Earth
Eva March Tappan

British Dictionary definitions for stratum

stratum

noun plural -ta (-tə) or -tums

(usually plural) any of the distinct layers into which sedimentary rocks are divided
biology a single layer of tissue or cells
a layer of any material, esp one of several parallel layers
a layer of ocean or atmosphere either naturally or arbitrarily demarcated
a level of a social hierarchy that is distinguished according to such criteria as educational achievement or caste status

Derived Formsstratal, adjective

Word Origin for stratum

C16: via New Latin from Latin: something strewn, from sternere to scatter

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

Word Origin and History for stratum

"horizontal layer," 1590s, from Modern Latin stratum, special use of Latin stratum "thing spread out, coverlet, pavement," from neuter past participle of sternere "to spread out, lay down, stretch out," from PIE *stre-to- "to stretch, extend," from root *stere- "to spread, extend, stretch out" (see structure (n.)).

stratum in Medicine

stratum

[strā′təm, străt′əm]

n. pl. stra•tums

A horizontal layer of material, especially one of several parallel layers arranged one on top of another.
Any of the layers of differentiated tissue forming an anatomical structure.

Related formsstra′tal (-təl) adj.

stratum in Science

stratum

[strā′təm, străt′əm]

Plural strata stratums

A layer of sedimentary rock whose composition is more or less the same throughout and that is visibly different from the rock layers above and below it.
A layer of tissue, as of the skin or another organ.