spy /spai/ I. n. ( pl.spies) 间谍，特务，密探：a police spy 警局密探；a military spy 军事间谍‖II.vi.&vt. 侦探，侦察(into, (up)on)：spy on the enemy’s movements 侦察敌方行动；spy into other people’s affair 窥探他人事物 I spied him trying to hide behind the tree. 我发现他企图躲到树后。