hidden

/ˈhɪd.ən/

形容词

不易找到的，隐藏的
There were hidden microphones in the room to record their conversation.
房间内有隐藏的话筒记录他们的对话。
不为人知的
Hidden problems may lead to an increase in costs.
预先不知道的问题可能导致成本的增加。