definition of
spy

[1] #1 spy n. [undercover agent] (military) a secret agent hired by a state to obtain information about its enemies or by a business to obtain industrial secrets from competitors. wn

[2] #2 spy v. [descry, spot, espy] catch sight of. wn

[3] #3 spy v. [stag, snoop, sleuth] watch, observe, or inquire secretly. wn

[4] #4 spy n. a secret watcher; someone who secretly watches other people; "my spies tell me that you had a good time last night". wn

[5] #5 spy v. [sight] catch sight of; to perceive with the eyes; "he caught sight of the king's men coming over the ridge". wn