火か山ざん前ぜん線せんかざんぜんせんMeanings1nounvolcanic frontrare termRare geological term referring to the boundary or zone where volcanic activity is concentrated, often in the context of subduction zones. The cross-reference 火山フロント is a more common synonym.See also: 火山フロント東とう北ほく日本にほん弧この火か山