unannounced

未事先通知的、突然的、臨時的

An unannounced inspection of the kitchen took place last Friday.

上週五廚房接受了一次未事先通知的檢查。

未公布的、未經宣布的

The company is still testing several unannounced products.

該公司仍在測試幾款尚未公布的產品。

未事先通知地、突然地

She showed up unannounced at my apartment on Sunday morning.

她星期天早上沒先說一聲就出現在我家。