stratum

[strey-tuhm, strat-uhm]

noun

plural

strata, stratums 

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.

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

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

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, phenomena.

Other Word Forms

• stratous adjective
• stratal 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

The kind you might have first met at a 4th of July picnic in a glass Pyrex dish, where guacamole and sour cream mingled with salsa and shredded cheese in slightly slouchy strata.

From Salon

I thought I wanted a piece of all that; not so much the affluence, but the ease with which he moved through the world with money and social strata no deterrence.

From Los Angeles Times

Each stratum, or layer, of our planet tells a story.

From Los Angeles Times

It’s easy to see why Chishiya has such a magnetic appeal at the close of a year when audiences obsessed over stories of con artists infiltrating society’s most exclusive strata.

From Salon

They seemed unbeatable — until good people from all strata of society rose up.

From Los Angeles Times