also: みっかでんか
short-lived rule; brief period in power; brief championship
A yojijukugo referring to a very short reign or period of dominance, often used metaphorically for any brief success or authority. The literal meaning is 'three-day reign', alluding to the historical figure Akechi Mitsuhide's short rule.
His brief reign as company president ended anticlimactically.
The championship team might also end up being a brief champion.