STRATUM, noun plural stratums or strata. The latter is most common. [Latin , to spread or lay.] 1. In geology and mineralogy, a layer; any species of earth, sand, coal and the like, arranged in a flat form, distinct from the adjacent matter. The thicker strata are called beds; and these beds are sometimes stratified. 2. A bed or layer artificially made.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI