A
cement is a
binder, a substance that sets and hardens and can bind other materials together. The word "cement" can be traced back to the
Roman term
opus caementicium, used to describe
masonry resembling modern
concrete that was made from crushed rock with
burnt lime as binder. The
volcanic ash and pulverized
brick supplements that were added to the burnt lime, to obtain a hydraulic binder, were later referred to as
cementum,
cimentum,
cäment, and
cement.