[ bak-dawr ]
See synonyms for backdoor on
nounAlso back door .
  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.

  1. an indirect manner or means: Marriage counseling was a kind of backdoor into therapy, where I finally faced my dysfunctional relationship with my mother.

  2. 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.

  3. Slang: Usually Vulgar. anus.

adjectiveAlso back-door .
  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.

  1. 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.

  2. Slang: Vulgar. anal (def. 1).

Origin of backdoor

First recorded in 1520–30; back1 + door Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use backdoor in a sentence

British Dictionary definitions for back door

back door

  1. a door at the rear or side of a building

    • a means of entry to a job, position, etc, that is secret, underhand, or obtained through influence

    • (as modifier): a backdoor way of making firms pay more

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with backdoor


An entry at the rear of a building, as in Deliveries are supposed to be made at the back door only. [First half of 1500s]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.