backdoor

American  

[bak-dawr] / ˈbækˈdɔr /

noun

1. a door at the rear of a house, building, etc..

   Fans were waiting by the backdoor of the theater, hoping to catch a glimpse of the band.

2. a secret, furtive, or illicit manner or means.

   The business has a backdoor through which the board of directors can access slush fund money.

3. an indirect manner or means.

   Marriage counseling was a kind of backdoor into therapy, where I finally faced my dysfunctional relationship with my mother.

4. Computers. a secret access point or undocumented vulnerability in a software program, hardware component, or digital network, sometimes intentionally maintained as for remote developer access, but also sometimes created or exploited for unauthorized access by hackers.

   If half of all devices have disclosed backdoors, cybersecurity experts must assume that the number of devices affected by undisclosed or malicious backdoors is much higher.

5. Slang: Usually Vulgar. anus.

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adjective

1. secret; furtive; illicit.

   Special interests pushed through a backdoor contract before the bidding period had expired.

2. indirect.

   The immigration reform bill included backdoor amnesty for employed undocumented residents.

3. Computers. relating to, using, or noting an indirect access point into a network, computer, or program.

   Hackers used a Trojan horse to establish backdoor access to the mainframe.

4. Slang: Vulgar. anal.

Etymology

Origin of backdoor

First recorded in 1520–30; back ¹ ( def. ) + door

Example Sentences

See Examples For:

backdoor

Separately, your husband’s consulting income may make him eligible for a “mega backdoor Roth” if his employer’s plan allows after-tax contributions and in-service Roth conversions.

From MarketWatch ● Jul. 20, 2026

Millions of digital home devices in the U.S. have pre-installed backdoor software, creating residential proxy networks used by nation-state hackers to mask cyberattacks.

From The Wall Street Journal ● Jun. 18, 2026

And the data is just starting to show trends for more recent law changes like in-plan conversions to Roth of after-tax contributions, known as mega backdoor Roth conversions and various types of automated features.

From MarketWatch ● Jun. 16, 2026

This gives anyone—including hackers—a backdoor into home networks.

From The Wall Street Journal ● Jun. 15, 2026

Trip came down and hit Glen on a backdoor play and we were up by one.

From "Slam!" by Walter Dean Myers

Related Words

• classified
• covert
• furtive
• hush-hush
• mysterious
• obscure
• private
• secluded
• undercover
• underground
• undisclosed
• unknown
• unpublished