Synonyms of undercover

undercover 1 of 3

adjective

ˌən-dər-ˈkə-vər 

1

as in clandestine

undertaken or done so as to escape being observed or known by others

an undercover operation to infiltrate the terrorist organization

Synonyms & Similar Words

• clandestine
• underground
• covert
• sneak
• private
• sneaking
• stealth
• secret
• surreptitious
• sneaky
• undisclosed
• behind-the-scenes
• stealthy
• furtive
• underhanded
• hole-and-corner
• backstairs
• underhand
• privy
• confidential
• hush-hush
• off-the-books
• hidden
• hugger-mugger
• classified
• closed-door
• off-the-record
• secreted
• concealed
• restricted
• top secret
• subterranean
• back-channel
• unexposed
• unadvertised

Antonyms & Near Antonyms

• public
• open
• overt
• avowed
• acknowledged
• straightforward
• unrestricted
• unclassified
• obvious
• unconcealed
• evident
• undisguised
• clear
• plain
• aboveboard
• manifest
• patent

2

as in covert

working on missions in which one's objectives, activities, or true identity are not publicly revealed

for months she's been an undercover agent pretending to be a drug dealer

Synonyms & Similar Words

• covert
• secret
• private
• secretive
• subterranean

Antonyms & Near Antonyms

• overt

undercover

2 of 3

noun

as in spy

a person who tries secretly to obtain information for one country in the territory of another usually unfriendly country

within the city was a well-organized fifth column, and these undercovers would make themselves known as soon as the invading forces breached the city limits

Synonyms & Similar Words

• spy
• operative
• agent
• mole
• undercover agent
• informer
• secret agent
• emissary
• asset
• spook
• courier
• sleeper
• intelligencer
• double agent
• counterspy
• infiltrator
• stool pigeon
• spymaster
• superspy

undercover

3 of 3

adverb

as in underground

Related Words

• underground
• surreptitiously
• stealthily
• secretively
• covertly
• clandestinely
• furtively
• underhanded
• sneakily
• underhandedly
• underhand
• collusively
• conspiratorially
• offstage
• offscreen
• secretly
• tête-à-tête
• à deux
• inwardly
• sotto voce
• privately
• backstage
• intimately
• confidentially
• in camera

Dissimilar Words

• publicly
• openly

Example Sentences

Recent Examples of undercover

Adjective

In 1979 two undercover police officers ticketed 125 guests and criminally charged nine others. — Aki Nace, CBS News, 25 June 2026

An undercover officer in an unmarked car spotted the vehicle and began following the suspects. — Fort Worth Star-Telegram, 23 June 2026

Noun

Le, who was working undercover, was shot while inside his vehicle after responding to one of multiple burglaries at a cannabis business on Embarcadero near Fifth Ave. — Carlos E. Castañeda, CBS News, 11 Dec. 2025

Four other agents accompanied me, all also operating undercover. — Martin Suarez, Rolling Stone, 13 Sep. 2025