backdoor

American

[bak-dawr] / ˈbækˈdɔr /

noun

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

The business has a backdoor through which the board of directors can access slush fund money.
an indirect manner or means.

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

adjective

secret; furtive; illicit.

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

The immigration reform bill included backdoor amnesty for employed undocumented residents.
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.
Slang: Vulgar. anal.

Etymology

Origin of backdoor

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

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.

In 2024, the Journal reported that Dubai’s main state-owned bank closed some accounts held by Russian oligarchs and oil traders after U.S. officials pressed the U.A.E. to shut Moscow’s backdoor to the international financial system.

From The Wall Street Journal • Mar. 6, 2026

The mega backdoor Roth won’t make you richer immediately, but it will allow your contributions to grow tax-free and to be withdrawn tax-free in retirement.

From MarketWatch • Jan. 9, 2026

It was designed to prevent civil lawsuits from becoming backdoor appeals of criminal judgments.

From Slate • Jan. 8, 2026

She went on to raise a series of concerns including "inadequate benefit levels" and "backdoor taxation for social care support".

From BBC • Dec. 30, 2025

Curious, Kendra rushed downstairs and out the backdoor.

From "Fablehaven" by Brandon Mull

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023