spies

NOUN

person who secretly finds out about another's business

Synonyms

STRONGEST

agent detective informer investigator mole operative secret agent secret service undercover agent

STRONG

emissary lookout observer patrol picket plant scout sleeper sleuth snoop spook spotter watcher

WEAK

double agent espionage agent foreign agent inside agent intelligencer

VERB

secretly follow, watch another's actions

Synonyms

STRONGEST

discover examine scrutinize snoop

STRONG

case eyeball glimpse meddle notice observe peep pry reconnoiter scout search shadow sleuth spot stag tail trail view watch

WEAK

catch sight of fish out get a load of keep under surveillance look for recon set eyes on stake out take in take note

Antonyms

STRONG

ignore miss neglect overlook

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

It also built up a network of spies across the developing world to foster revolution.

From The Wall Street Journal • Jul. 5, 2026

As the Times describes the order, he wants the intelligence agencies to “turn over the names” of all foreign spies, “including suspected spies and potential recruits” on a single all-in-one-place list.

From Slate • Jul. 1, 2026

In 1978, Scappaticci, who died in 2023, was put on a new IRA security unit specifically tasked with flushing out spies within its ranks.

From BBC • Jun. 30, 2026

Foreign spies were seeking to recruit Australians to reveal official secrets about AUKUS, the country's security partnership with Britain and the United States.

From Barron's • Jun. 24, 2026

To keep that from happening, the United States needed inside information about the plans of South America’s Nazi sympathizers and the spies who were working with them.

From "The Woman All Spies Fear" by Amy Butler Greenfield