prior warning/noticeBEFOREa warning or announcement made before something happens 预先警告/通知 The society must give customers prior notice before changing the cost. 调整费用之前协会必须预先通知客户。
The bomb exploded without any prior warning. 没有任何预先警告，炸弹就爆炸了。
without ... prior warning• Note: Don't ever send an attachment of more than a few hundred kilobytes without prior warning or agreement.• You can imagine my surprise, then, when Pikey, without prior warning, started to hum like a top.
→ prior warning/notice at prior1(1)