Definition of master key in US English:

master key

noun

  • A key that opens several locks, each of which also has its own key.

    ‘the custodian has the master key to all the classrooms’
    • ‘‘There was no reply and we tried the master key but the latch was on so we tried looking though the windows and saw Paul lying on the floor,’ she said.’
    • ‘The change key will open only that specific lock, while the master key will open that lock and several others in a group.’
    • ‘‘I used my master key and managed to open the door just a little to get my hand and arm in to push it back into the room,’ recalls Mike.’
    • ‘Letting herself in with a master key, Viviane began to relax as she stepped into her house.’
    • ‘The janitor here had said the last time she'd used her master keys to get me in that it was the absolute last time ever.’
    • ‘Pari took Stella to her room and opened the door with a master key.’
    • ‘The gap in security is this: The system allows someone with only one office key, and access to the lock, to create a master key for himself.’
    • ‘When the officer responding to the call arrived, he used his master key to remove the citizen's key.’
    • ‘She pulled out a master key from her pocket and unlocked the door.’
    • ‘She made her way to the storage room and unlocked it with the master key she wore on her neck.’
    • ‘Nelson reached into his pocket, and took out his master key.’
    • ‘A fellow sub-warden then went to check on her, finally using her master key to enter her room where she made the horrifying discovery.’
    • ‘I got the master key and opened the door and that's when I saw him in the bath.’
    • ‘She removed the master key she'd secretly made and unlocked the door.’
    • ‘One master key is much better than having to deal with 25 different keys.’
    • ‘Using his master key Kip unlocked one of the loading dock doors to the mall and went inside.’
    • ‘He unraveled the cloth, and inside was a pack of saws, picks, rakes, default master keys, and other sorts of lock making and lock picking materials.’
    • ‘Equipped with master keys to all main doors in the council estate, torches and radios, the wardens patrol the estate from 10 am - 10 pm six days a week.’
    • ‘She used her master key to open the lock, and began to open the gate.’
    • ‘In high-rise office buildings and hotels, use a separate master key for each floor or wing, thus restricting key decoding to limited areas.’

Pronunciation

master key

/ˈmastər ˈˌkē//ˈmæstər ˈˌki/