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adstratum

[ad-strey-tuh m, -strat-uh m]
noun, plural ad·stra·ta [ad-strey-tuh, -strat-uh] /ˈædˌstreɪ tə, -ˌstræt ə/. Historical Linguistics.
  1. a substratum or superstratum.

Origin of adstratum

ad- + stratum
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018