superstratum

noun

su·​per·​stra·​tum ˈsü-pər-ˌstrā-təm 

-ˌstra-;

ˌsü-pər-ˈstrā- 

-ˈstra-

plural superstrata ˈsü-pər-ˌstrā-tə 

-ˌstra-;

ˌsü-pər-ˈstrā-,

-ˈstra-

: an overlying stratum or layer

The superstratum of timidity which often overlies those who are daring and defiant at heart had been passed through …

—Thomas Hardy

Word History

First Known Use

1703, in the meaning defined above