noun, noun which may take the genitive case particle 'no'
volcano
Refers to a geological volcano. Also used attributively with の to mean 'volcanic'.
富士山は活火山です。
Mt. Fuji is an active volcano.
火山活動が活発になっている。
Volcanic activity is becoming more active.
Compound of 火 (か, 'fire') and 山 (さん, 'mountain'), literally 'fire mountain'. The reading かざん is a straightforward on'yomi combination.