Synonyms of spy in English:

spy


See US English definition of spy

See UK English definition of spy

See Spanish definition of espía

noun

1‘the government had planted two spies in the organization’

SYNONYMS
secret agent, undercover agent, enemy agent, foreign agent, secret service agent, intelligence agent, double agent, counterspy, industrial spy, fifth columnist, mole, plant, scout
control, handler
North American spook
informal snooper
archaic intelligencer
archaic, informal beagle

verb

1‘she spied some asparagus on a stall’

SYNONYMS
notice, observe, see, spot, sight, catch sight of, glimpse, catch a glimpse of, get a glimpse of, make out, discern, pick out, detect, have sight of
informal clap eyes on, lay eyes on, set eyes on
literary espy, behold, descry

2‘the couple were spied on by reporters’

SYNONYMS
observe furtively, keep under surveillance, watch, keep a watch on, keep an eye on, keep under observation, follow, shadow, trail
informal tail
rare surveil

3‘he agreed to spy for the West’

SYNONYMS
be a spy, be engaged in spying, gather intelligence, work for the secret service
informal snoop