stratum

/ˈstrɑːtəm/ (bre, ipa) · /ˈstreɪtəm/ (ame, ipa) · /ˈstrā-təm ˈstra-/ (ame, mw)

stratum — noun

  • stratumsingular
  • strataplural

1. A distinct level or grade that forms one part of a multi-layered structure, in c

1.名詞B2
釋義

A distinct level or grade that forms one part of a multi-layered structure, in contexts ranging from geology and biology to society and culture.

例句

The advanced stratum of Dr. Chen's writing workshop covers academic essays and research papers.

stratum + of + noun for a graded level

Elena's piano exam belongs to the most difficult stratum of the graded syllabus.

stratum of a graded system

同義詞
  • layer

    more everyday and concrete; 'layer of tissue' is interchangeable but 'layer of meaning' sounds less technical than 'stratum of meaning'

  • level

    broader and less formal; works for hierarchies and abstractions but lacks the stacked-image of 'stratum'

  • tier

    suggests a carefully ordered series, often used for ranks or seating; more artificial than 'stratum'

文法句型

stratum + of + noun phrase describing the layered system

用法筆記

The plural form is strata, not 'stratums'. This sense is common in formal, academic, and scientific writing across many fields.

常見錯誤

❌The researcher examined the stratum of the society.
✅The researcher examined the strata of society.
💡'stratum' is singular; use 'strata' when referring to multiple layers.

2. A clearly defined band of natural material — rock, soil, sand, or sediment — tha

2.名詞B2
釋義

A clearly defined band of natural material — rock, soil, sand, or sediment — that lies between other bands in the ground.

例句

The miners broke through a hard stratum of granite before reaching the coal seam.

collocation: stratum of [rock type]

A thin stratum of clay separates the two layers of sandstone in this valley.

stratum + of + material name

同義詞
  • layer

    the everyday alternative; 'layer of rock' is more common in general speech, while 'stratum' is the formal geology term

  • bed

    a technical geology synonym for a single distinct layer of sedimentary rock

文法句型

stratum + of + rock/soil/clay type

用法筆記

In geology, stratum is the standard technical term. The plural strata is very common because rock formations typically contain multiple layers.

常見錯誤

❌This area has three different stratums of limestone.
✅This area has three different strata of limestone.
💡The Latin plural 'strata' is the only correct form in geology.

3. A group within a society whose members share a similar economic position, level

3.名詞B2
釋義

A group within a society whose members share a similar economic position, level of education, or social status.

例句

Education offers a path for people to move from one social stratum to another.

social stratum (core collocation)

The upper stratum of wealthy families controlled most of the city's land.

upper stratum / lower stratum

同義詞
  • class

    the more common and less formal term; 'working class' is everyday language, while 'lower stratum' sounds like sociology

  • rank

    suggests a clear ordering within a hierarchy, often in an organisation rather than in society at large

  • caste

    a more rigid, inherited social division; much stronger and more specific than 'stratum'

文法句型

stratum + of + society/population

用法筆記

More academic and formal than 'class'. In sociology, 'social stratum' is preferred over 'social class' when the boundaries between levels are seen as continuous rather than sharply divided.

常見錯誤

❌People from all stratums of society attended the festival.
✅People from all strata of society attended the festival.
💡'strata' is the plural, even in social contexts.