back door

noun

A subsidiary entrance to a building or house at its rear, normally away from the street.

Similar
backgatebackdoorback entrance

Meanings

nounback door (countable and uncountable, plural back doors)

plural back doors · alternative backdoor · alternative back-door

  1. countableuncountableA subsidiary entrance to a building or house at its rear, normally away from the street.

    "Charles II, who was crowned here a little while before, occupied an old house (which is still standing) in New Street [Worcester], from which he escaped by the back door, as the enemy rushed in at the front."

    2023 January 11, Stephen Roberts, “Bradshaw's Britain: castles and cathedrals”, in RAIL, number 974, page 57
  2. countableuncountableA means of access, often secret and unprotected, to something.

    Scoring three goals at home should guarantee you three points, but when you go on the attack a little bit more, you leave the back door open. That's not always a good idea with this team.

    2021 November 29, Alan Shearer, “Why Newcastle have to win their next two games to give them hope of staying in the Premier League - Alan Shearer analysis”, in BBC Sport
  3. countableuncountablecomputer securityA secret means of access to a program or system.
  4. countableuncountableautomotiveA rear side door of a car, or at the back of a van.
  5. countableslanguncountableThe anus (usually in sexual practices).

    backdoor action

    1 more example

    go up the back door

    Synonyms: backgate

  6. broadlyslanguncountableAnal sex.

    Oh, don't be so judgmental. You could use a little back door.

    1998 June 28, Michael Patrick King, “Valley of the Twenty-Something Guys”, in Sex and the City, season 1, episode 4, spoken by Samantha
  7. countableinformaluncountablegolfThe rear side of the hole, furthest from the golfer.

    Sometimes the ball will curve around and enter from the back-door.

    2010, Bob Glanville, Golf: The Game of Lessening Failures, page 14
adjectiveback door (not comparable)

alternative backdoor · alternative back-door

  1. USnot comparableball gamesThe path of a pitch which starts outside and then slides over the plate.

    He has a nasty back door slider.

  2. not comparableAchieved through indirect means.

    Lately there's been a lot of back door pressure on me to step down.

  3. not comparablecard gamesRequiring consecutive cards on the turn and river to be achieved.
    1 more example

    The flop had the ace of spades, queen of spades, and two of diamonds, and I was holding the king of spades and the three of hearts. I bet big, hoping for a jack and a ten to make my back door straight-draw, or a spade to make my back door flush-draw. But when the turn card was the five of clubs, I had to fold.

verbback door (third-person singular simple present back doors, present participle back dooring, simple past and past participle back doored)

present singular third person back doors · participle present back dooring · participle past back doored · past back doored · alternative backdoor · alternative back-door

  1. To attempt to accomplish by indirect means, especially when direct means are proscribed.
  2. transitivehobbiesTo enter a tube by accelerating from behind; to surf into an already formed hollow wave, in contrast to the normal method of slowing to allow a surfable wave to form.

    If you survive the heavy take-off at 'The Chair' (which is very close to the rocks) you will find you're in 'The Suck-up', which offers either a spectacular barrel or a bonecrunching wipeout, but you might find you have to back door it.

    1999, Mark Warren, Mark Warren's Atlas of Australian Surfing, traveller's, →ISBN, page 103
  3. transitivecomputer securityTo add a backdoor (a secret means of access) to a program or system.

    Now that we have backdoored the notepad.exe binary, we will go back to the Meterpreter session and upload our backdoor: 3. Then, we need to start a listener so we. meterpreter > upload notepad-backdoored.exe [*] uploading[…]

    2018 February 26, Abhinav Singh, Nipun Jaswal, Monika Agarwal, Daniel Teixeira, Metasploit Penetration Testing Cookbook: Evade antiviruses, bypass firewalls, and exploit complex environments with the most widely used penetration testing framework, 3rd Edition, Packt Publishing Ltd, →ISBN, page 213
    2 more examples

    As an example, the generation algorithm for backdoored Dual EC picks a fixed group element Q, a random exponent d, and outputs as public key the pair P = Qd and Q. The secret key is d. (We use multiplicative notation for simplicity.)[…]

    2015 April 13, Elisabeth Oswald, Marc Fischlin, Advances in Cryptology – EUROCRYPT 2015: 34th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Sofia, Bulgaria, April 26-30, 2015, Proceedings, Part I, Springer, →ISBN, page 103

    Back in the session, we will rename the httpd.exe file to httpd.exe.backup, upload the backdoored version, and rename it to httpd.exe: msf exploit(handler) > sessions -i 1 [*] Starting interaction with 1... meterpreter > cd[…]

    2019 July 18, Gilberto Najera-Gutierrez, Juned Ahmed Ansari, Daniel Teixeira, Abhinav Singh, Improving your Penetration Testing Skills: Strengthen your defense against web attacks with Kali Linux and Metasploit, Packt Publishing Ltd, →ISBN, page 453
  4. slangtransitiveTo betray (someone); to double-cross (someone); to set (someone) up; to take advantage of (someone's) trust.

Synonyms & antonyms

nounThe anus (usually in sexual practices).

Similar

More synonyms by meaning

nouna secret or underhand means of access (to a place or a position)

Similar
Broader

nounan undocumented way to get access to a computer system or the data it contains

Similar

nounan entrance at the rear of a building

Similar
backdoorback entrance
Broader
exterior dooroutside door

Synonym sets from Open English WordNet, CC BY 4.0.

Translations

Arabic بَاب خَلْفِيّ
  • بَاب خَلْفِيّ (bāb ḵalfiyy)subsidiary entrance to building
Bulgarian за́ден вход, гъз
  • за́ден вход (záden vhod)subsidiary entrance to building
  • гъз (găz)slang: anus
Chinese Cantonese 後門 /后门, 後門 /后门
  • 後門 /后门 (hau⁶ mun⁴)subsidiary entrance to building
  • 後門 /后门 (hau⁶ mun⁴)secret, unprotected means of access
  • 後庭 /后庭 (hau⁶ ting⁴)slang: anus
Chinese Mandarin 後門 /后门, 後門 /后门
  • 後門 /后门 (hòumén)subsidiary entrance to building
  • 後門 /后门 (hòumén)secret, unprotected means of access
  • 後庭 /后庭 (hòutíng)slang: anus
  • 後門 /后门 (hòumén)slang: anus
Danish bagdør, bagdør
  • bagdørsubsidiary entrance to building
  • bagdørsecret, unprotected means of access
  • bagdørautomotive: rear door
  • bagdørcomputing: secret means of access
Dutch achterdeur, achterdeur
  • achterdeursubsidiary entrance to building
  • achterdeursecret, unprotected means of access
Finnish takaovi, sivuovi
  • takaovisubsidiary entrance to building
  • sivuovisubsidiary entrance to building
  • takaovisecret, unprotected means of access
  • takaporttisecret, unprotected means of access
  • takaoviautomotive: rear door
  • takaluukkuautomotive: rear door
  • takaovislang: anus
  • takaportticomputing: secret means of access
  • tunkeutuato attempt to accomplish by indirect means
German Hintertür, Hintertür
  • Hintertürsubsidiary entrance to building
  • Hintertürsecret, unprotected means of access
  • hintere Seitentürautomotive: rear door
  • Hecktürautomotive: rear door
  • Backdoorcomputing: secret means of access
Greek κερκόπορτα
  • κερκόπορτα (kerkóporta)secret, unprotected means of access
Hungarian hátsó ajtó/bejárat, kiskapu
  • hátsó ajtó/bejáratsubsidiary entrance to building
  • kiskapusecret, unprotected means of access
  • kerülőútsecret, unprotected means of access
Icelandic leynilegur, laumulegur
  • leynilegursecret, unprotected means of access
  • laumulegursecret, unprotected means of access
Italian porta di dietro, porta di servizio
  • porta di dietrosubsidiary entrance to building
  • porta di serviziosubsidiary entrance to building
  • porta sul retrosubsidiary entrance to building
  • backdoorcomputing: secret means of access
  • ottenere per vie traverseto attempt to accomplish by indirect means
Japanese 裏口, 裏戸
  • 裏口 (uraguchi)subsidiary entrance to building
  • 裏戸 (urado)subsidiary entrance to building
  • 裏門 (uramon)subsidiary entrance to building
  • 裏口 (uraguchi)secret, unprotected means of access
  • 裏戸 (urado)secret, unprotected means of access
  • 裏口 (katteguchi)secret, unprotected means of access
  • 裏門 (uramon)secret, unprotected means of access
  • バックドア (bakkudoa)computing: secret means of access
Korean 뒷문, 후문
  • 뒷문 (dwinmun)subsidiary entrance to building
  • 후문 (humun)subsidiary entrance to building
  • 뒷문 (dwinmun)secret, unprotected means of access
  • 백도어 (baekdo'eo)computing: secret means of access
Latin postīcum
  • postīcumsubsidiary entrance to building
Norwegian Bokmål bakdør, bakdør
  • bakdørsubsidiary entrance to building
  • bakdørsecret, unprotected means of access
Polish tylne drzwi, tylne drzwi
  • tylne drzwisubsidiary entrance to building
  • tylne drzwisecret, unprotected means of access
  • tylne drzwiautomotive: rear door
  • tyłekslang: anus
  • backdoorcomputing: secret means of access
  • robić potajemnieto attempt to accomplish by indirect means
  • zrobić potajemnieto attempt to accomplish by indirect means
Portuguese porta dos fundos, porta traseira
  • porta dos fundossubsidiary entrance to building
  • porta traseirasubsidiary entrance to building
  • porta de trássubsidiary entrance to building
  • porta do cavalosubsidiary entrance to building
  • porta dos fundossecret, unprotected means of access
  • porta traseiraautomotive: rear door
  • porta de trásautomotive: rear door
  • backdoorcomputing: secret means of access
Russian за́дняя дверь, за́дний вход
  • за́дняя дверь (zádnjaja dverʹ)subsidiary entrance to building
  • за́дний вход (zádnij vxod)subsidiary entrance to building
  • чёрный ход (čórnyj xod)secret, unprotected means of access
  • потайна́я дверь (potajnája dverʹ)secret, unprotected means of access
  • жо́па (žópa)slang: anus
  • бэкдо́р (bɛkdór)computing: secret means of access
  • чёрный ход (čórnyj xod)computing: secret means of access
  • лазе́йка (lazéjka)computing: secret means of access
Spanish puerta trasera, puerta de atrás
  • puerta traserasubsidiary entrance to building
  • puerta de atrássubsidiary entrance to building
Swedish bakdörr, baksätesdörr
  • bakdörrsubsidiary entrance to building
  • baksätesdörrautomotive: rear door
Ukrainian за́дні две́рі, чо́рний хід
  • за́дні две́рі (zádni dvéri)subsidiary entrance to building
  • чо́рний хід (čórnyj xid)secret, unprotected means of access
  • потайні́ две́рі (potajní dvéri)secret, unprotected means of access
  • ду́па (dúpa)slang: anus
Vietnamese đi cửa sau, chạy cửa sau
  • đi cửa sauto attempt to accomplish by indirect means
  • chạy cửa sauto attempt to accomplish by indirect means
Welsh drws cefn
  • drws cefnsubsidiary entrance to building
Cite this entry
APA

back door. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/back%20door

MLA

“back door.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/back%20door. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “back door,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/back%20door.

Source: back door on Wiktionary, CC BY-SA 4.0.