stratum

/ˈstreɪɾəm/

/ˈstreɪtəm/

Other forms: strata; stratums

A stratum is a layer of something, whether abstract, like a social stratum composed of only billionaires, or physical, like the different strata (that’s the plural version) of clouds that an airplane passes through.

Stratum comes from the Latin meaning "something that has been laid down," like asphalt or a bedsheet, but we generally use it to describe layers of something. If you go into geology, you will probably investigate different strata of the soil. If you start out in life poor and try to become rich, you are trying to get into a different social stratum.

Definitions of stratum

1. noun

   one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism or a layer of sedimentary rock)
   types:

   cuticle, epidermis

   the outer layer of the skin covering the exterior body surface of vertebrates

   corneum, horny layer, stratum corneum

   the outermost layer of the epidermis consisting of dead cells that slough off

   stratum lucidum

   the layer of epidermis immediately under the stratum corneum in the skin of the palms and soles

   stratum granulosum

   the layer of epidermis just under the stratum corneum or (on the palms and soles) just under the stratum lucidum; contains cells (with visible granules) that die and move to the surface

   malpighian layer, rete Malpighii, stratum basale, stratum germinativum

   the innermost layer of the epidermis

   corium, derma, dermis

   the deep vascular inner layer of the skin

   cambium

   the inner layer of the periosteum

   paries, wall

   (anatomy) a layer (a lining or membrane) that encloses a structure

   substrate, substratum

   any stratum or layer lying underneath another

   superstrate, superstratum

   any stratum or layer superimposed on another

   horizon

   a specific layer or stratum of soil or subsoil in a vertical cross section of land

   bed, seam

   a stratum of ore or coal thick enough to be mined with profit

   bed

   (geology) a stratum of rock (especially sedimentary rock)

   mantle, pallium

   (zoology) a protective layer of epidermis in mollusks or brachiopods that secretes a substance forming the shell

   abdominal wall

   a wall of the abdomen

   soil horizon

   a layer in a soil profile

   geological horizon

   a layer of rock with a particular composition (especially of fossils); for dating the stratum

   coal seam

   a seam of coal

   ore bed

   a stratum of ore

   type of:

   layer

   a relatively thin sheetlike expanse or region lying over or under another
2. noun

   people having the same social, economic, or educational status
   synonyms: class, social class, socio-economic class

   types:

   domain, world

   people in general; especially a distinctive group of people with some shared interest

   age class

   people in the same age range

   agriculture

   the class of people engaged in growing food

   brotherhood, fraternity, sodality

   people engaged in a particular occupation

   estate, estate of the realm, the three estates

   a major social class or order of persons regarded collectively as part of the body politic of the country (especially in the United Kingdom) and formerly possessing distinct political rights

   labor, labour, proletariat, working class

   a social class comprising those who do manual labor or work for wages

   lower class, underclass

   the social class lowest in the social hierarchy

   bourgeoisie, middle class

   the social class between the lower and upper classes

   booboisie

   class consisting of all those who are considered boobs

   commonality, commonalty, commons

   a class composed of persons lacking clerical or noble rank

   peasantry

   the class of peasants

   demimonde

   a class of woman not considered respectable because of indiscreet or promiscuous behavior

   underworld

   the criminal class

   yeomanry

   class of small freeholders who cultivated their own land

   caste

   a social class separated from others by distinctions of hereditary rank or profession or wealth

   caste

   (Hinduism) a hereditary social class among Hindus; stratified according to ritual purity

   upper class, upper crust

   the class occupying the highest position in the social hierarchy

   ninja

   a class of 14th century Japanese who were trained in martial arts and were hired for espionage and assassinations

   firing line

   the most advanced and responsible group in an activity

   immigrant class

   recent immigrants who are lumped together as a class by their low socioeconomic status in spite of different cultural backgrounds

   center

   politically moderate persons; centrists

   old school

   a class of people favoring traditional ideas

   market

   the customers for a particular product or service

   craft, trade

   people who perform a particular kind of skilled work

   fair sex, woman, womanhood

   women as a class

   Lords Spiritual, first estate

   the clergy in France and the heads of the church in Britain

   Lords Temporal, second estate

   the nobility in France and the peerage in Britain

   Commons, third estate

   the common people

   fourth estate

   the press, including journalists, newspaper writers, photographers

   labor force, labor pool

   the source of trained people from which workers can be hired

   lumpenproletariat

   (Marxism) the unorganized lower levels of the proletariat who are not interested in revolutionary advancement

   organized labor

   employees who are represented by a labor union

   petit bourgeois, petite bourgeoisie, petty bourgeoisie

   lower middle class (shopkeepers and clerical staff etc.)

   academe, academia

   the community or environment of colleges and universities

   Grub Street

   the world of literary hacks

   jati

   (Hinduism) a Hindu caste or distinctive social group of which there are thousands throughout India; a special characteristic is often the exclusive occupation of its male members (such as barber or potter)

   elite, elite group

   a group or class of persons enjoying superior intellectual or social or economic status

   aristocracy, gentry

   the most powerful members of a society

   people in power, ruling class

   the class of people exerting power or authority

   black market

   people who engage in illicit trade

   type of:

   people

   (plural) any group of human beings (men or women or children) collectively
3. noun

   an abstract place usually conceived as having depth
   “the mind functions on many strata simultaneously”

   synonyms: layer, level

   type of:

   place

   an abstract mental location