C 间谍，特务，密探a person employed to find out secret information, especially from an enemy or a competitor in business

　We have a spy among us.　我们中间有一个间谍。
　It seemed that she was a spy because she knew what everyone was doing.　她似乎是个密探，因为她知道每个人的举动。

1. vt. & vi.窥探　 act as a spy on; watch secretly
2. vt. & vi.观察　 observe; see; discover

　～ the horseman　看到骑者
　～ the way　侦察出一条路
　～ artfully　狡猾地窥探
　～ bravely　勇敢地窥探
　～ breathlessly　匆忙窥探
　～ briefly　短暂地窥探
　～ carefully　仔细地搜查
　～ cautiously　小心翼翼地观察
　～ challengingly　具有挑战性地窥探
　～ deliberately　故意窥探
　～ generally　一般性地窥探
　～ importunately　急切地窥探
　～ instinctively　本能地窥探
　～ involuntarily　不由自主地观察
　～ patiently　耐心地窥探
　～ purposely　有目的地窥探
　～ scrupulously　谨慎地窥探
　～ selectively　有选择地窥探
　～ sententiously　故作庄严地窥探
　～ slyly　偷偷摸摸地观察
　～ spontaneously　自然地窥探
　～ successively　连续窥探
　～ thoroughly　彻底地搜查窥探
　～ tirelessly　不知疲倦地窥探
　～ unkindly　非善意地窥探
　～ unscrupulously　肆无忌惮地观察
　～ out　察出
　～ into　调查
　～ on　窥探，监视

　They left at daylight in order to spy the way.　他们在黎明出发，目的是侦察出一条路。
　He was the first to spy the horseman in the distance.　他最先看到出现在远处的骑者。
　Our look-out spied a man hiding in some bushes.　我们的哨兵察觉有人藏在树丛中。
　We spied them coming through the gate.　我们发现他们穿过这道门。

 ♣ spy into　(v.+prep.)
　调查　look into
　Tom began to spy into a complicated affair.　汤姆开始调查一件复杂的事件。
　The old lady likes spying into other people's affairs.　这个老太太喜欢窥探他人的事情。
 ♣ spy on　(v.+prep.)
　窥探；监视　pry about; peep at
　She often spies on her neighbours.　她经常窥探邻居。
　He was paid by the police to spy on other students.　他受警察雇佣监视其他学生的行动。
 ♣ spy out　(v.+adv.)
　察出　examine; look into
　The detective spied out the suspected thief.　侦探察出了被怀疑的贼。

　［词源］古英语spien<古法语espier（间谍）