火か山ざん砂さかざんさMeanings1nounvolcanic sandrare termRare technical term for sand-sized tephra ejected by a volcano; in everyday contexts, 火山灰 (volcanic ash) is more common.火か山ざん砂さは粒りゅう径けいが2mm以い下かの火か山ざん噴ふん出しゅつ物ぶつを指さす。Volcanic sand refers to volcanic ejecta with a grain size of 2 mm or less.
