1Fine granular particles of broken-down rock, found on beaches, in sandboxes, deserts, etc. The reading すな is standard; いさご is a poetic, old-fashioned way to say the same thing.
子どもたちは公園の砂場で山を作って遊んだ。
The children played by building a mountain in the park's sandbox.
この海岸は白くて細かい砂で有名だ。
This beach is famous for its fine white sand.
靴の中に砂が入って歩きにくい。
Sand got into my shoes, making it hard to walk.
風が吹くたびに砂が舞い上がる砂漠を旅した。
We traveled through a desert where sand billowed up every time the wind blew.