idiom · to stop an activity, campaign, or project, often to avoid notice or following a failure (literally by lowering flags and silencing drums)

这里的建筑工程由于资金短缺，不得不偃旗息鼓。

idiom · to stop an argument, fight, or effort and concede defeat or withdraw

在铁证如山的证据面前，他只好偃旗息鼓，不再辩解。