三日天下 みっかてんか Also written みっかでんか Meanings Noun short-lived rule; being in power only for a brief period; brief championship Kanji 三 three. Read as み. 日 day 天 heaven. Read as テン. 下 down. Read as カ. Word lists Yojijukugo (四字熟語) Jinuma: Japanese Dictionary · Word lists