stratum

[ strey-tuhm, strat-uhm ]

noun

, plural stra·ta [strey, -t, uh, strat, -, uh], stra·tums.

1. a layer of material, naturally or artificially formed, often one of a number of parallel layers one upon another:

   a stratum of ancient foundations.

2. one of a number of portions or divisions likened to layers or levels:

   an allegory with many strata of meaning.

3. Geology. a single bed of sedimentary rock, generally consisting of one kind of matter representing continuous deposition.
4. Biology. a layer of tissue; lamella.
5. Ecology. (in a plant community) a layer of vegetation, usually of the same or similar height.
6. a layer of the ocean or the atmosphere distinguished by natural or arbitrary limits.
7. Sociology. a level or grade of a people or population with reference to social position, education, etc.:

   the lowest stratum of society.

8. Linguistics. (in stratificational grammar) a major subdivision of linguistic structure. Compare level ( def 17 ).

stratum

/ ˈstrɑːtəm /

noun

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

stratum

/ strā′təm,străt′əm /

, Plural strata

1. 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.
2. A layer of tissue, as of the skin or another organ.

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. agenda, criterion, media, phenomena.

Derived Forms

• ˈstratal, adjective

Other Words From

• stratous adjective

Word History and Origins

Origin of stratum¹

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

Word History and Origins

Origin of stratum¹

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

Example Sentences

My eye catches the calm and smooth stratum of gray clouds that approach from the south.

From The Daily Beast

But their young deputies and ministerial director generals tended to be from this recently-returned, Western-educated stratum.

From The Daily Beast

People who do well do not deserve what they have gotten - they got it because they were born into the right social stratum.

From The Daily Beast

They were born into the wrong social stratum, or were handicapped by personal weaknesses that were not their fault.

From The Daily Beast

And lifting them carefully one off the other, he took out a deal box that had stood in the lowest stratum.

From Project Gutenberg

It is only a lower stratum, but still it is a part of terra firma, and on no account is it to be ignored.

From Project Gutenberg

They reached a depth in his nature which had been long untouched; a stratum, so to speak, which lay far beneath the surface.

From Project Gutenberg

I thought that the frozen surface of the American woman thawed on the stratum soubrette.

From Project Gutenberg

Reddish, very quartzose sandstone; from a stratum which dips to the south-east, at an angle of about ten or fifteen degrees.

From Project Gutenberg