- a key that will open a number of different locks, the proper keys of which are not interchangeable.
Origin of master key
First recorded in 1570–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for master key
I shall mention two, though one is sufficient for a master-key to them all.Rembrandt and His Works
She had provided herself with a master-key which opened all the doors.Odd Volume
This is the State secret; this is the master-key to the whole policy.
Analysis: The master-key is the key that opens all the doors of the asylum.
Love is the master-key that opens every ward of the heart of man.
- a key that opens all the locks of a set, the individual keys of which are not interchangeableAlso called: pass key
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