master key

noun

1. a key that will open a number of different locks, the proper keys of which are not interchangeable.

master key

noun

1. Also called: pass key. a key that opens all the locks of a set, the individual keys of which are not interchangeable

Word History and Origins

Origin of master key¹

First recorded in 1570–80

Example Sentences

At 15:19, she tried the door to the toilet, using a master key to unlock it.

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Staff had master keys that could unlock all the patients' rooms.

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"As we have said many times before, we have never built a backdoor or master key to any of our products or services and we never will."

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The company claims he sold a “master key” for $350 that facilitated cheating across a range of games.

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"As we have said many times before, we have never built a backdoor or master key to any of our products or services and we never will," Apple says on its website.

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