noun

• (countable, uncountable) A powdered substance produced by firing (calcining) calcium carbonate (limestone) and clay that develops strong cohesive properties when mixed with water. The main ingredient of concrete.
  "In the autumn there was a row at some cement works about the unskilled labour men. A union had just been started for them and all but a few joined. One of these blacklegs was laid for by a picket and knocked out of time."
• (uncountable) The paste-like substance resulting from mixing such a powder with water, or the rock-like substance that forms when it dries.
• (uncountable) Any material with strong adhesive and cohesive properties such as binding agents, glues, grout.
• (figurative) A bond of union; that which unites firmly, as persons in friendship or in society.
  "the cement of our love"

verb

• (transitive) To affix with cement.
• (transitive) To overlay or coat with cement.
  "to cement a cellar floor"
• (transitive, figurative) To unite firmly or closely.
  "For they have entertained cause enough To draw their swords: but how the fear of us May cement their divisions and bind up The petty difference, we yet not know."
• (figuratively) To make permanent.
  "But friendſhip is a calm and ſedate affection, conducted by reaſon and cemented by habit; ſpringing from long acquaintance and mutual obligations; without jealouſies or fears; and without thoſe feveriſh fits of heat and cold, which cauſe ſuch an agreeable torment in the amorous paſſion."