Definitions

master key

NOUN

key opening all locks of a place

Synonyms

WEAK

opener pass'-partout passkey skeleton key

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Antibodies can sometimes act like a master key, helping trigger immune responses.

From Science Daily • Jan. 9, 2026

"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.

From BBC • Mar. 14, 2025

Mitchell also went into Blanchard’s chambers in 2023 by using a master key, the commission wrote.

From Los Angeles Times • Feb. 13, 2025

Why it's important: Your SSN is a master key to your financial life.

From Salon • Aug. 27, 2024

I had the master key because another one of my summer jobs was assistant apprentice super for my family’s complex.

From "The Epic Fail of Arturo Zamora" by Pablo Cartaya