understratum

[uhn-der-strey-tuh m, -strat-uh m]
noun, plural un·der·stra·ta [uhn-der-strey-tuh, -strat-uh] /ˈʌn dərˌstreɪ tə, -ˌstræt ə/, un·der·strat·ums.
  1. a substratum.

Origin of understratum

First recorded in 1725–35; under- + stratum
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for understratum

Historical Examples of understratum