Real Dictionary

sandstone
variable noun: Sandstone is a type of rock which contains a lot of sand. It is often used for building houses and walls.

sandstone in American English
a common bedded sedimentary rock much used for building, composed largely of sand grains, mainly quartz, held together by silica, lime, etc.
noun: a common sedimentary rock consisting of sand, usually quartz, cemented together by various substances, as silica, calcium carbonate, iron oxide, or clay

sandstone in British English
noun: any of a group of common sedimentary rocks consisting of sand grains consolidated with such materials as quartz, haematite, and clay minerals: used widely in building