spy /spaɪ/ (spies, spying, spied) ► SEE ALLspy on sb/sthspy sth out ●ˈspy on sb/sth ( ˈspy upon sb/sthmore formal) to watch sb/sth secretly暗中监视；窥探；侦查◆He hired a detective to spy on his wife. 他雇了侦探暗中监视他的妻子。◆He knew he was being spied on. 他知道有人正在秘密监视他。[v + prep]●ˌspy sth ˈout (BrE) to go somewhere secretly to try to find out information（去某处）暗中查明，秘密查出◆I arrived early to spy out the land(= collect information before deciding what do do). 我很早便到了，以便摸清情况。◆He studied the map and spied out the quickest route. 他研究了一下地图，发现了一条最便捷路线。[v + adv + n][v + pron + adv][v + n + adv] (rare)