spy on (someone or something)

To observe someone or something in a clandestine or furtive manner, so as not to be noticed doing so. I can't believe you hired a private detective to spy on me—do you really distrust me that much? I was sent to spy on the foreign ambassador during his time in Washington.

spy out

1. To observe or investigate something or some place very closely or carefully in order to discover something or glean some information. A noun or pronoun can be used between "spy" and "out." We sent our best agents to spy the enemy encampment out in order to find a weak spot. I've been spying out some land to the west of town that could be suitable for our farm.

2. To discover something or glean some information as a result of close, careful observation. A noun or pronoun can be used between "spy" and "out." I've been sent to spy out what goes on behind closed doors at this factory. We so far haven't been able to spy any motive out for the attack.

spy out the land

To find out about or come to understand a particular state of affairs or the way a situation exists or has developed, especially before taking any decisive or definitive action. Given the turbulent nature of this market, I think it would be prudent for us to spy out the land before we agree to invest in your company. I'm just spying out the land regarding my parents' divorce before I make any solid plans to come visit them this Christmas.

ˌspy out the ˈland

find out about a situation, a place, an organization, etc. before you make a decision: The manager is sending Mark to Iceland to spy out the land. He wants to know whether we can do business there.

spy out

1. To observe some place secretly and closely: The troops spied out the cave and decided it was safe to hide there. The explorers sent a scout into the valley to spy it out before descending.

2. To discover something by observing secretly and closely: Try to spy out what's going on on those rooftops. We followed the other teams' strategies carefully to spy them out.