Spy Definition

spī

spied, spies, spying

noun

spies

A person employed by a government to get secret information about or monitor the affairs, plans, armed forces, etc. of another government.

Webster's New World

One who secretly collects information for a business about one or more of its competitors.

American Heritage

A person who keeps close and secret watch on another or others.

Webster's New World

A person employed by a company, as in industry or commerce, to discover the business secrets of another company.

Webster's New World

An act of spying.

Webster's New World

Synonyms:

Synonyms:
undercover agent
mata-hari
mole
secret-service agent
intelligencer
emissary
double-agent
espionage agent
wiretapper
watcher
detective
counterspy
counterintelligence agent
secret-agent
intelligence agent

verb

spied, spies, spying

To watch or observe closely and secretly, usually with unfriendly purpose.

Webster's New World

To watch or observe closely and secretly; specif., to act as a spy.

Webster's New World

To make a close examination or careful inspection.

Webster's New World

To catch sight of; make out; perceive; see.

Webster's New World

To engage in espionage.

American Heritage

Synonyms:

adjective

Of or about spies or espionage.

Webster's New World

Used for purposes of military espionage.

Spy plane, spy satellite.

Webster's New World

idiom

spy out

to discover or seek to discover by close observation, inspection, etc.

Webster's New World

Other Word Forms of Spy

Noun

Singular:

spy

Plural:

spies

Idioms, Phrasal Verbs Related to Spy

spy out

Origin of Spy

Middle English spien, aphetic variant of earlier espien "to espy", from Old French espier (“to spy") (espie "a spy"), from Frankish *spehōn (“to spy"), from Proto-Germanic *spehōnÄ… (“to see, look"), from Proto-Indo-European *spek- (“to look"). Akin to Old High German spehōn, spehhōn "to scout, look out for, spy" (German spähen "to spy"), Middle Dutch spien "to spy", Dutch bespieden "to spy on".

From Wiktionary
Middle English spie from Old French espie from espier to watch of Germanic origin spek- in Indo-European roots

From American Heritage Dictionary of the English Language, 5th Edition