Good evening and welcome to Word of the Day! A journey through the English vocabulary and the words that piqued my interest, in WotD we'll be learning a new word for each working day of the week, bar holidays, unless there's a holiday special...

Today's word is:

stratum

|ˈstrātəm, ˈstra-|

noun ( pl. strata |ˈstrātə, ˈstra-| )

1. A layer or a series of layers of rock in the ground: a stratum of flint.

  • A thin layer within any structure: thin strata of air.

2. A level or class to which people are assigned according to their social status, education, or income: members of other social strata.

  • Statistics a group into which members of a population are divided in stratified sampling.

ORIGIN: late 16th cent. (in the sense 'layer or coat of a substance'): modern Latin, from Latin, literally 'something spread or laid down,' neuter past participle of sternere 'strew.'

Usage: In Latin, the word stratum is singular and its plural form is strata. In English, this distinction is maintained. It is therefore incorrect to use strata as a singular: a new stratum was uncovered (not a new strata was uncovered). It is also wrong to create the form stratums or stratas as the plural: a series of overlying strata (not overlying stratums or overlying stratas ).