master key


plural master keys
: a key designed to open any of a set of similar locks (as on the doors of a building)
The porter unlocked the door with his master key.Paul Wilkinson
… he borrowed the electronic master key …—a fob which unlocks all the bedrooms in the building—and used it to enter another resident's room.Jason Evans
… the … idea of coordinating luggage inspection by providing locks that the TSA can open with a master key.Ryan Davis

called also passkey

: something (such as a set of computer instructions or a specific sequence of characters) that provides digital access to a variety of systems, files, etc.
… an alarmingly powerful cipher … that could be used as a master key to bypass basically any security system imaginable …Sara Netzley
The cybercriminals behind the … ransomware have decided to close up shop and have now released the master key capable of decrypting files locked with their malware.Anthony Spadafora
You can store all your passwords in one database, which is locked with a master key. So you only have to remember one single master key to unlock the whole
: a crucial means of understanding or attaining something
usually used with to
That's when it clicked. I had trained my mind to think what I wanted. At that point, I knew mindset training was the master key to success.David DeRam
One approach to defeating aging suggests replacing body parts as they fail. Another aims at finding a master key to youth.Todd Friend
… a man I thought might hold the master key to one of the strangest scholarly mysteries in recent decades …Ariel Sabar

Examples of master key in a Sentence

Recent Examples on the Web Letter carriers have also been on alert for much of the year following a rash of armed robberies, where packages or the carrier’s master key are taken. Vivian La, Chicago Tribune, 27 July 2023 The agency also suggested improving security measures, such as by adding peepholes in bedroom doors, restricting access to master keys that can open multiple dorm rooms and giving field personnel more satellite phones. Margaret Osborne, Smithsonian Magazine, 6 Sep. 2023 Microsoft was then able to search its own logs for the master key that the hackers had obtained and block future access. Joseph Menn, Washington Post, 15 Aug. 2023 Solving the Trump problem is the master key to this election, and no one has found it. Trip Gabriel, Chicago Tribune, 10 Aug. 2023 In the most robberies, armed thieves target mail carriers’ master keys. Laura Rodríguez Presa, Chicago Tribune, 8 Apr. 2023 Opponents also say the bill would weaken Miya’s Law, which strengthened safety measures for apartment residents It was named after Miya Marcano, a 19-year-old Valencia College sophomore from Pembroke Pines killed in 2021 by an apartment maintenance worker who had a master key to her apartment. Jeffrey Schweers, Orlando Sentinel, 23 Mar. 2023 Crooks often are trying to get their hands on checks in the mail or a master key, which can open multiple blue mailboxes in an area. Susan Tompor, Detroit Free Press, 16 Mar. 2023 The door to the classroom finally was opened when the principal produced a master key, state and federal law enforcement officials said. Tim Stelloh, NBC News, 26 May 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'master key.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1577, in the meaning defined at sense 1

Time Traveler
The first known use of master key was in 1577

Dictionary Entries Near master key

Cite this Entry

“Master key.” Dictionary, Merriam-Webster, Accessed 30 Sep. 2023.

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