- 1[uncountable] a type of hard stone that is usually white and often has colored lines in it. It can be polished and is used in building and for making statues, etc. a slab/block of marble a marble floor/sculpture
- 2[countable] a small ball of colored glass that children roll along the ground in a game
- 3 marbles [uncountable] a game played with marbles Three boys were playing marbles.
- 4 marbles [plural] (informal) a way of referring to someone's intelligence or mental ability He's losing his marbles (= he's not behaving in a sensible way).