earshot

例句：

1. 1. She overheard a conversation between her boss and his secretary.
   她无意中听到了老板和他的秘书之间的对话。
2. 2.The spy eavesdropped on the enemy's communications to gather intelligence.
   间谍通过窃听敌人的通信来收集情报。
3. 3.They listened in on a meeting that was supposed to be confidential.
   他们偷听了一个本应保密的会议。