Definition of "superstratum" [su•per•stra•tum]

• One layer or stratum superimposed on another. (noun)
• Linguistics The language of a later, invading people imposed on and leaving features in an indigenous language. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The whole superstratum, which is oftentimes many feet in thickness, consists of the debris of vegetable and animal matter; for these swamps are scarcely more noted for their luxuriant vegetation, than they are for their abundance of insects and reptiles."
• "[M3] “is on” means the substratum-superstratum relation."
• "Like in France, where the result of the contact of Gaulish Latin, as a spoken substratum, with superstratum Frankish only surfaced in writing in the ninth century after the Carolingian Reform, it needed a strong external impetus to adjust the written language to the spoken practice."