flagstone

/ˈflæɡ.stəʊn/

Etymology

From flag + stone.

flagstone means A flat, rectangular piece of rock or stone used for paving or roofing. Lexicurio rates it Rare gem — a strength score of 83 out of 100.

noun

A flat, rectangular piece of rock or stone used for paving or roofing.“Grass sprouted between the pebbles and a greenish stain lay upon the flagstones.”
One of several types of rock easily split and suitable for making flagstones.