From Longman Dictionary of Contemporary Englishflagstoneflag‧stone /ˈflæɡstəʊn $ -stoʊn/ noun [countable] TBa smooth flat piece of stone used for floors, paths etc
Examples from the Corpus
flagstone• I asked what was the oldest part of the farm and was shown a flagstone path leading down to a valley.• He stumbled around the side of the house, over broken flagstones, toward a light shining above the back door.• Joe Asnett looked up as they walked unsteadily into the small flagstone floored back room.• Then she landed on the Market Square flagstones with a sickening crash to lie motionless.• Nicole and Bernard, or whatever his name is, getting carved up on the flagstone.• The grey mass fell on to the flagstones. 