- A key that opens several locks, each of which also has its own key: the custodian has the master key to all the classroomsMore example sentences
- The change key will open only that specific lock, while the master key will open that lock and several others in a group.
- She used her master key to open the lock, and began to open the gate.
- I got the master key and opened the door and that's when I saw him in the bath.
More definitions of master keyDefinition of master key in:
- The British & World English dictionary