godan verb (-su)
dance all night; dance until dawn
Describes dancing through the night until morning. Often used in festive or celebratory contexts.
夏祭りで、みんなで踊り明かした。
We danced all night at the summer festival.
彼らは朝まで踊り明かすつもりだ。
They plan to dance until morning.
Compound of 踊り (dancing) and 明かす (to pass the night). The verb 明かす here means to spend the whole night doing something.