Daily Chinese Idiom Guessing Game
To end a matter by leaving it unresolved; to let something fizzle out without proper closure.
了了结，结束。用不了结的办法去了结。指把事情放在一边不管，就算完事。
宋·叶少蕴《避暑录话》卷上唐人言冬烘是不了了之语，故有‘主司头脑太冬烘，错认颜标是鲁公’之言。人以为戏谈。”
The committee meetings were so boring that they just let the proposal 不了了之.