- 1a gray powder made by burning clay and lime that sets hard when it is mixed with water. Cement is used in building to stick bricks together and to make very hard surfaces. Use a mixture of one part cement to four parts sand.
- 2the hard substance that is formed when cement becomes dry and hard a floor of cement a cement floor see also concrete, mortar
- 3a soft substance that becomes hard when dry and is used for sticking things together or filling in holes dental cement (= for filling holes in teeth)
- 4(formal) something that unites people in a common interest values which are the cement of society