secret
Definitions
Kept from the knowledge or view of others; hidden.
Known only to a limited number of people; confidential.
A piece of information that is meant to be kept unknown or hidden from others.
Examples
She whispered a secret into his ear so no one else could hear.
The recipe for their famous sauce remains a closely guarded secret.
He felt relieved after finally sharing his long-held secret with a friend.
Synonyms
confidential covert hidden private clandestine stealthy undisclosed