Base"ment (&?;), n. [F. soubassement. Of uncertain origin. Cf. Base, a., Bastion.] (Arch.) The outer wall of the ground story of a building, or of a part of that story, when treated as a distinct substructure. (See Base, n., 3 (a).) Hence: The rooms of a ground floor, collectively.
Basement membrane (Anat.), a delicate membrane composed of a single layer of flat cells, forming the substratum upon which, in many organs, the epithelioid cells are disposed.
Base"ness (&?;), n. The quality or condition of being base; degradation; vileness.
I once did hold it a baseness to write fair.
Shak.