電光石火 でんこうせっか Meanings Noun, の-adjective flash; instant; lightning (speed) Kanji 電 electric. Read as デン. 光 light. Read as コウ. 石 stone. Read as セキ. 火 fire. Read as カ. Example sentences 電光石火の速さで走った。I ran like lightning. 彼はそれを電光石火の早さで仕上げた。He finished it as quick as lightning. Word lists Yojijukugo (四字熟語) Jinuma: Japanese Dictionary · Word lists