Is there any specific word that describes or denotes a key, which helps thief to steal anything and anywhere, no matter what kind of lock there is. In a nut shell that key can unlock any locks e.g. of room, wardrobe, bike, etc.

In some parts of Pakistan, people regard such keys in Urdu as under:

ﭼﻮﺭ ﭼﺎﺑﯽ

Translation: 'thieving key'.

In translation, I used the adjective thieving which I got from Internet.

'the thieving key'.

But 'thieving' describes a person, rather than any material... perhaps, there might be an adjective or a noun describing or denoting a key, which can unlock anything, and can open the doors for the thieves to steal easily.


I thought that the two-worded phrase master key might help here, but it totally connotes positivity of the key, about which I am not after:

master key (noun, From Oxford English Living Dictionaries.)

  1. a key that opens several locks, each of which also has its own key. [IMO, it has positive connotation]

See that, in a hotel, a master key can be held by any hotel workers, and those keys are not made for the thieves.

There should be a word having negative connotation, as mentioned previously in Urdu: thieving key.

The thief had [adjective] key.


The thief had [noun for that key].

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    It's a hypothetical key. And the use of the term is mere metaphorical. There may be no direct equivalent in other languages.
    – Kris
    Commented Oct 9, 2018 at 11:42
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    Positive or negative connotation depends on context: Thieves use master key to get into buildings, steal mail in San Francisco abc7news.com/news/thieves-use-master-key-to-steal-mail-in-sf/…
    – user 66974
    Commented Oct 9, 2018 at 11:42
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    @user240918 They must have stolen the master key first to do that.
    – Kris
    Commented Oct 9, 2018 at 11:43
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    For the old style locks, 50-100 years ago, it was generally called a "skeleton key" in the US. But these don't work on modern cylinder locks -- must obtain the specific "master key" (if there is one), or simply "pick the lock" with a "lock pick".
    – Hot Licks
    Commented Oct 9, 2018 at 11:50
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    Alo​ho​mora​? Commented Oct 9, 2018 at 15:12

11 Answers 11


Skeleton key has been suggested by many other answers, but always as a secondary suggestion. That would be incorrect: it is the correct answer here. No other answer suggested, possibly excepting the archaic passe-partout, has this meaning.

A skeleton key is a key which has been specially made so that it will open many different locks.


Many dictionaries, as well as Wikipedia, will tell you about the original design of a skeleton key: a key with all the ridges filed away so that it can open many locks. It’s actually where the name comes from, as stripping off the ridges was said to leave only the key’s “skeleton.” Anyway, that design only works on rather basic locks known as warded locks. Warded locks are not much in use anymore, largely because of the vulnerability to skeleton keys, therefore the original skeleton key design is not generally all that useful for theft.

On the other hand, the term skeleton key has outlived the original design, and is often used to describe a hypothetical key that opens any lock, rather than just those susceptible to the original skeleton design. For instance,

Many times refers to a magical key that will sucessfully unlock anything.

(Urban Dictionary—note that by the third definition, the term has become a euphemism for sex, as most Urban Dictionary definitions eventually end up doing)

Used metaphorically, then, skeleton key means a key that will open any lock. Given the sophistication of modern locks, and the many different designs for them, this is generally treated as a magical ability, since no actual key could open all of those different locks. In my experience, the metaphorical usage of skeleton key is far more common than the specific historical design that it is named after.

Master Key

A master key is a key which will open all the locks in a set, even though each lock has its own different key.

(Collins Dictionary)

Master keys are legitimate tools intentionally used by property owners, not thieves’ tools. For example, if you own a hotel, you might have the locks for your doors made with a master key, and then give it to the cleaning staff.

Generally speaking, the master key has to be made first—if you just have a random set of locks it will be extremely difficult, and probably just impossible, to come up with a master key for all of them.

If a thief got their hands on a master key for a building or whatever that they wished to rob, it makes the theft very easy, of course, but ultimately this is no different from stealing the key or keys that open whatever you need. The master key is easier because it’s one key that opens many locks.

Pass Key

The word pass key can mean master key, or it can mean skeleton key. When used to mean skeleton key, it can have this meaning, but the fact that it can instead mean master key makes it less than useful here.



Universal Key

Universal key is not a common term, and I can find no dictionary that includes it. A quick Google search suggests that by far the most common usage for this term is a “universal handcuff key,” a simple cylinder with a little “flag.” Per comments by Aziris Morora and mrog, handcuffs all use this same, simple design, so you can actually get a standardized key that will open all of them. But it won’t open anything else.

Anyway, not what you are looking for.

Lock picks and bump keys

On the other hand, lock picks and bump keys are definitely used as theives’ tools, as well as used legitimately by locksmiths. They can be used to open up locks with some skill and effort. Many locks are very easy to pick; many locks are nearly, if not outright, impossible to pick. Either way, lock picking is a skill and these tools help; they don’t just open the lock automatically for you.

Importantly, even though a bump key is called a “key,” it doesn’t really work like one—you can’t just stick it in, turn it, and expect the lock to open. Instead, you have to “bump” the lock to get it to open. However, it’s worth noting that the bump key does bear some similarities to the original design of the skeleton key—like the skeleton key was filed smooth to foil cylinder locks, the bump key consists of several unusually-sharp points which can be used to “bump” pin–tumbler locks. Like the original skeleton key, the bump key is not useful for other lock designs. Unlike skeleton key, though, bump key has not reached the quasi-legendary status that skeleton key has, and it is not used for a hypothetical key-for-all-locks.

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    You'd be surprised about police handcuffs. The vast majority use 'cuffs with this very simple lock.
    – Pierre P.
    Commented Oct 11, 2018 at 16:13
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    @AzirisMorora is correct. Handcuffs typically use very simple warded locks. You can easily buy keys that work with any common brand of handcuff. This makes life easier for the police because they don't have to hunt for a specific matching key whenever they use their handcuffs.
    – mrog
    Commented Oct 11, 2018 at 18:09
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    This is an excellent answer but it's worth just pointing out that lock picks are not the preserve of thieves, and may be used legitimately by locksmiths, called by people who have locked themselves out of their house for example. This explains why lock picking tools can be bought legally. Commented Oct 12, 2018 at 8:52
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    I like how skeleton key responds to the OP’s note about connotation; unless you’re an orthopaedist, skeletons I imagine skeletons would evoke disconcerting emotions. Commented Oct 14, 2018 at 19:43
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    @AnthonyX While researching this, I have seen a few places use them interchangeably. Prior to doing so, I had never once heard them used that way at all, and I don’t personally consider them interchangeable. In my experience, using skeleton key when you mean master key, or vice versa, is wrong. I’d also add that even while researching this, most do not consider them interchangeable. If you wish to write an answer claiming otherwise, be my guest, but I disagree with that usage.
    – KRyan
    Commented Oct 14, 2018 at 22:55

The things that thieves actually use to open doors is called a lockpick or picklock. These are actually quite tricky to use, and won't work on all locks, although they do work on many of them.

A master key is something that is made to open all the locks in one building or set of buildings. Generally, managers and janitors have these. But these (or at least, the ones in actual use) don't open all locks; just locks that have been made so as to be opened by this specific key.

A skeleton key is a key that has been (probably illicitly) filed down so that it will open all of some particular class of locks. I don't believe that skeleton keys work on most modern locks, but they do work on old-fashioned types of locks, and so in the past they would have been very useful to thieves.

If you are talking about some mythical key that opens all doors easily, I don't believe there is such a myth in the English-speaking world. If such a myth actually existed, it might be called a

universal key,

and in fact, Googling universal key shows that it indeed has been used with this meaning

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    "Skeleton key" was (relatively) universal on old "warded" locks. Won't work for modern cylinder locks.
    – Hot Licks
    Commented Oct 9, 2018 at 11:55
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    The only problem with the term "lockpick" is that if the OP wants a work for a "key," a lockpick don't look like a key - the simplest version (which works fine if you know how to use it!) is just a piece of bent wire.
    – alephzero
    Commented Oct 9, 2018 at 12:42
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    +1 for universal key. As it answers the OP's question well. OP asked for a key that can unlock any lock, hence, universal key is better option here.
    – Eugene
    Commented Oct 9, 2018 at 13:14
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    Even though skeleton keys only worked on some locks and such locks haven't been used in a long time, the phrase has survived and morphed to mean "a key to unlocking (something / anything)." IMHO.
    – stannius
    Commented Oct 9, 2018 at 16:17
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    As @Stannius said, I'd definitely argue that "Skeleton Key" as a phrase is understood as a key that opens all doors. It's definitely the commonly used term for an enchanted or magical key of this type in most fantasy works + RPG games. Commented Oct 9, 2018 at 18:00

You are probably looking for passe-partout:

something that secures entry everywhere, esp a master key

Also skeleton key or passkey:

A skeleton key is a key which has been specially made so that it will open many different locks.

(Collins Dictionary)

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    I agree that this is great option, but it's an archaic term.
    – Ahmed
    Commented Oct 9, 2018 at 11:16
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    "Skeleton key" is exactly what OP is looking for. Passkey would probably fit, but, like "master key", implies legitimacy. I like passe-partout, but it really isn't in common use. Commented Oct 9, 2018 at 11:52
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    +1 to Skeleton key...and it would be helpful to the OP to know which word is being upvoted/downvoted if you answered just one word per answer. Commented Oct 9, 2018 at 12:49
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    +1 for skeleton key as this is the one according to OPs clarification. The main difference (missing in the answer) is that a master key is a key intended for a set of locks, e.g. all locks in a specific building. This is usually used by someone with a high access to all premises. If a thief gets hand on one they'll access any room in the specific building (which helps in a theft for sure) but they need to steal the key (or obtain it some other way). A skeleton key is a key used to open a lock for which you don't have a valid key, i.e. to pick a lock. And that's what thieves do (and own).
    – Ister
    Commented Oct 9, 2018 at 13:05
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    @user240918 My mother tongue is German, and the German word "Dietrich" was the word that came into my mind immediately. A quick dictionary lookup showed "skeleton key", "picklock" and "lockpick". IMHO, "passe-partout" is more common for the wide border between a picture and its frame. Commented Oct 9, 2018 at 15:31

You could call it a master key

: a key designed to open several different locks

  • Similarly, hotel rooms around the world are vulnerable to a hack that lets an intruder mimic a hotel's master key and open any door.

Brian Barrett, WIRED, "Security News This Week: The Biggest DDoS For Hire Site Goes Down," 28 Apr. 2018

or a skeleton key

a key that will open several doors

Thieves may have used 'skeleton key' in Wigan break-ins

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    Perhaps worth noting that a skeleton key is a specific subtype of master key—a key with elements filed down to bypass the parts of a (poorly designed) lock that actually do the locking, instead operating the actuator directly. It is possible to create a master key for a set of properly designed locks without any of them being vulnerable to a skeleton key.
    – Anko
    Commented Oct 9, 2018 at 11:56

What about a master key

master key (noun)

  1. a key that opens several locks, each of which also has its own key.

(Oxford Living Dictionaries)

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    Oldest correct answer! Commented Oct 9, 2018 at 12:30
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    This not the correct answer. A master key is custom made to order for a specific set of locks. If a thief has it or the ring of keys that also open the specific set of locks, they only have access to those specific locks. Commented Oct 9, 2018 at 16:14

In terms of what modern thieves are likely to actually use, consider bump key.

Bump keys are specific to a lock type, effectively single use and they require considerable force to work. They are quite inelegant, although very effective and extremely fast to operate - they work in seconds.

Lock bumping is a lock picking technique for opening a pin tumbler lock using a specially crafted bump key, rapping key or a 999 key.


Lock bumping is a trend in burglaries, which can make it easy and fast to break into homes without needing too much special equipment or leaving any trace of forced entry. It works almost as well as actually having a key, and a set of ten rapping keys can make the criminals capable of opening 90% of common tumbler locks. However, criminals might choose to avoid lock bumping when stealth is required, because of the noisiness of the process. Almost all tumbler locks are vulnerable to bumping.

(However, I think you have already got an equivalent expression to your thief's key in skeleton key, which is dated enough to have charm, is a word children would know, and also has a hint of the sinister about it.)

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    Any of the better in-patent locks (Primus, Medeco etc.) will be resistant to bumping because they use really weird keyways that have additional keying in the keyway that won't bump. Only the mfgr. Can make the odd keyway features and only your locksmith can obtain them. They cost about $70 per tumbler set and $13 per key, and they go in higher quality knobsets that cost a fortune (by big-box store residential standards). Would I use one on my house? You bet your bippy. Commented Oct 9, 2018 at 20:41

If we get away from the practicalities of whether such keys exist in reality and look at keys which do exist in fairy-tales and other fiction, we find a clear distinction between a master key which is made with good intent, and only available to the thief by theft, deception etc., and a skeleton key which is made with evil intent. Supernatural forces are often used, either to actually make the key or to find out how to. A third method is to take an ordinary key and cast a spell on it. Whatever method you use the principle is that a skeleton key is the most widely understood term for a universal key made with evil intent and found in stories.


Other answers have suggested this, but to make it clearer, no such key exists. A master key can open many locks, but not all. And even when there were skeleton keys in common use, there were also locks of other types, just as today there are tumbler locks with flat keys to lift pins, flat keys where the pins fit in holes on the flat side, and tubular keys (and several other types).


Perhaps, people might consider it a pass key.

pass key noun

  1. a key to the door of a restricted area, given only to those who are officially allowed access.

  2. a master key.

(Cambridge Dictionary)


If it is for one building only, we can also speak of a "Maison Key", although this is generally for common areas. Security personnel may have a "Grand Master" or "Great Grand Master" key as well depending upon pinning.

In recent times we have not strictly a key, but a shaker, which emulates the action of a "rake" from a "pick" set. These are battery powered and will open most yale locks at some slight risk of lock damage. Put some torque on the cylinder and agitate the pins with one of these and the cylinder will turn when all columns of pins will allow shear.

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    Or I've done it with a small screwdriver and a paperclip.
    – Hot Licks
    Commented Oct 12, 2018 at 1:27

Counterfeit Master Key - This is a phrase often used to describe what would be a loose translation of 'thieving key' - "SAN JOSE (KRON) — Viewer video appears to show a man stealing mail from a South Bay neighborhood using a counterfeit master key." -https://www.postaltimes.com/postalnews/viewer-video-shows-man-using-counterfeit-master-key-steal-mail/ (10.10.2018)

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    Another answer already proposes "Master Key". Counterfeit is a separate consideration unrelated to it being a master key: it simply means an illegal copy of the original. You can have a counterfeit master key in the same way that you can have a counterfeit Rolex or counterfeit banknote. Commented Oct 10, 2018 at 5:18

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