Noun
-
a secret watcher
someone who secretly watches other people
"my spies tell me that you had a good time last night"
-
(military) a secret agent hired by a state to obtain information about its enemies or by a business to obtain industrial secrets from competitors
- undercover agent
Verb
-
secretly collect sensitive or classified information
engage in espionage
"spy for the Russians"
-
catch sight of
to perceive with the eyes
"he caught sight of the king's men coming over the ridge"
-
watch, observe, or inquire secretly
-
catch sight of