stratum
Concise Oxford English Dictionary © 2008 Oxford University Press:
stratum /ˈstrɑːtəm, ˈstreɪtəm/
▶noun (pl. strata /-tə/)
- 1 a layer or a series of layers of rock.
- 2 a thin layer within any structure.
- 3 a level or class of society.
– origin C16: mod. L., from L., lit. ‘something spread or laid down’, neut. past part. of sternere ‘strew’.
usage: In English, as in the original Latin, stratum is singular and its plural form is strata. It is therefore incorrect to use strata as a singular or to create the form stratas as the plural: a series of overlying strata not a series of overlying stratas, and a new stratum was uncovered not a new strata was uncovered.
'stratum' also found in these Oxford entries:
bed
- cross-bedding
- dip
- fossiliferous
- fracture
- interbed
- ledge
- pan
- strata
- stratal
- stratigraphy
- stratum corneum
- strike
- subsurface
- superstratum
- underclass
