stonestonestonesstonedstoningnoun1(no plural) the very hard material that is in the ground. Stone is sometimes used for building: a stone wall2(pluralstones) a small piece of stone: The children were throwing stones into the river.3(pluralstones) the hard part in the middle of some types of fruit: Peaches, plums, cherries and olives all have stones.4(pluralstones) a small piece of beautiful rock that is very valuable: A diamond is a precious stone.5(pluralstone) (British) a measure of weight equal to 6.35 kg. There are 14 pounds in a stone: I weigh ten stone.Look at the note at pound.