From Italian basamento 'foundation course,' ultimately from Greek básis 'step, pedestal.'
The floor of a building which is partly or entirely below ground level.
From base + -ment. The architectural term was borrowed from Italian basamento 'base of a column' in the 18th century, blending with English base (from Latin basis, from Greek básis 'step, pedestal'). Originally an architectural term for the lowest story of an Italian palazzo. Key roots: *gwem- (Proto-Indo-European: "to come, go, step").