stratum

英 [ˈstrɑːtəm]

美 [ˈstreɪtəm]

n. 层; 岩层; 地层; 阶层

复数：strata　

Collins.1 / BNC.8071 / COCA.11902

牛津词典

noun

N-COUNT 社会阶层
Astratumof society is a group of people in it who are similar in their education, income, or social status.
1. It was an enormous task that affected every stratum of society...
  这是一项影响到社会各阶层的重大工作。
2. The rebels came overwhelmingly from the poorest strata of rural society.
  叛乱分子绝大多数来自农村的最贫困阶层。
N-COUNT 岩层
Strataare different layers of rock.
1. Contained within the rock strata is evidence that the region was intensely dry 15,000 years ago.
  岩层中有证据表明，该地区在 15,000 年前曾经非常干旱。

noun

an abstract place usually conceived as having depth
1. a good actor communicates on several levels
2. a simile has at least two layers of meaning
3. the mind functions on many strata simultaneously
Synonym:levellayer
people having the same social, economic, or educational status
1. the working class
2. an emerging professional class
Synonym:classsocial classsocio-economic class
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)

An aquifer is a water-bearing rock stratum such as sandstone and chalk.
地下蓄水层是一些有水的岩石层，如沙岩和白垩岩。
The permeability barrier is located in the outermost layer of the epidermis, the stratum corneum.
这层通透性屏障位于表皮的最外层-角质层。
It was an enormous task that affected every stratum of society
这是一项影响到社会各阶层的重大工作。
This evolution is stratum accumulation but not replacement.
这种演进是“层累”式的，而并非是“替换”式的。
A thin layer or stratum, as of coal or rock.
薄薄的一层或层面，如煤或岩石的。
The stratum of main source rock among the marine facies is the upper Sinian and the Paleozoic group.
其中海相地层中的主力烃源岩层为上震旦统和上古生界石炭―二叠系。
They represent each society stratum.
他们代表各个社会阶层。
Let us choose a particular social stratum.
让我们挑选某个特定的社会阶层。
And it also can remain in the stratum corneum, exacerbating irritation.
而且它还会遗留在角质层中，加剧对肤质的刺激。
It means, the modern embryonic form of social stratum structure has formed.
可以说，现代化的社会阶层结构的雏形已经形成。