1. (n.) The act of espying; notice; discovery.

2. (n.) One who espies; a spy; a scout.

bringing to light bugging casual discovery catching chance discovery cloak-and-dagger work counterespionage counterintelligence detection determination determining disclosure discovery distinguishment electronic surveillance espionage excavation exhumation exposure find finding finding out following intelligence intelligence work invention locating location looking lookout lucky strike military intelligence note notice observance observation recognition rediscovery regard respect revelation secret police secret service serendipity shadowing spotting spying stakeout strike surveillance tailing trailing treasure trove trouvaille trove uncovering unearthing viewing watch watching wiretap wiretapping witnessing