Meaning of the word "three may keep a secret, if two of them are dead" in English

What does "three may keep a secret, if two of them are dead" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

three may keep a secret, if two of them are dead

US /θriː meɪ kiːp ə ˈsiːkrət, ɪf tuː əv ðəm ɑːr ded/
UK /θriː meɪ kiːp ə ˈsiːkrət, ɪf tuː əv ðəm ɑː ded/
"three may keep a secret, if two of them are dead" picture

Idiom

a proverb suggesting that secrets are only safe when no one else knows them, as people are generally unable to keep secrets

Example:
I wouldn't tell anyone else about the plan; remember, three may keep a secret, if two of them are dead.
He lives by the cynical rule that three may keep a secret, if two of them are dead.