光明石 こうめいせき Also written こうみょうせき Meanings Noun kōmeiseki; kōmei stone (i.e.: slightly radioactive stone used in onsens, traditional medicine, etc.) Kanji 光 light. Read as コウ. 明 clear. Read as メイ. 石 stone. Read as セキ. Jinuma: Japanese Dictionary · Word lists