rhizoverbBeta
DictionarystratumPhysical layer
noun

stratum

STRAY-tum/ˈstreɪtəm/

A distinct layer within a larger body.

The rust-red stratum lies between pale and gray rock layers.

Compact cutaway block of sedimentary rock with several thin layers; one thick rust-red horizontal band is exposed prominently between pale and gray bands, making a single stratum unmistakable.
Etymology
stratumLatinto spread out; lay down

Something ‘spread out’ could be a bedspread or pavement: a covering laid across a surface. That image underlies a horizontal layer, extended figuratively to a level within society or another structure.

In context

Dr Dray1:38
when you exfoliate what you're doing is taking away part of the stratum corneum and kind of evening out that top top dead layer
How to exfoliate your face and body| Dr Dray

More examples

  • Each stratum of rock records a different period of deposition.
  • The core sample contains several strata of compacted sediment.
  • The policy affects every stratum of society.

Forms

stratum · strata · stratums

stratify verb — To arrange or form into distinct layers.

stratification noun — The arrangement or division into distinct layers.

Similar words

layer
A broader, everyday term for material covering or underlying something.
bed
Usually a deposited layer of sediment or sedimentary rock.