volcanic ejecta; tephra; cinders; scoria
Refers to solid material ejected during a volcanic eruption, such as cinders, scoria, and other pyroclastic fragments. Used in geological and disaster-related contexts.
Volcanic ejecta flew out of the crater.
Be careful not to be hit by volcanic cinders while climbing.
Compound of 噴 (ふん, 'erupt') and 石 (せき, 'stone'), literally 'erupted stone'. The reading is on'yomi.