Euthynteria
From Infogalactic: the planetary knowledge core
Euthynteria is the ancient Greek term for the uppermost course of a building's foundations, partly emerging from groundline. The superstructure of the building (stereobate and stylobate, columns, walls, and entablature) were set on the euthynteria. Archaeologists and architects use the term in discussion of Classical architecture.
References
Robertson, D. S. 1929. Handbook of Greek and Roman Architecture. Cambridge: Cambridge University Press