To see at a distance; catch sight of or discover at a distance.To see or discover suddenly, after some effort, or unexpectedly, as by accident: with reference to some person or thing in a degree concealed or intended to be hidden: as, to espy a man in a crowd.To inspect narrowly; explore and examine; observe and keep watch upon; spy.Synonyms To discern, descry, perceive, catch sight of.To look narrowly; keep watch; spy.n. A spy; scout; watch.n. Espial; espionage.