the state of being secret
"you must respect the confidentiality of your client's communications"
discretion in keeping secret information
"The lawyer assured her client that strict confidentiality would be maintained regarding their case details."
The property of being confidential.
"The strict confidentiality required by her job meant she could never discuss client details outside the office."
In plain English: Confidentiality means keeping private information secret and not sharing it with anyone else without permission.
"The doctor promised to keep all patient information confidential."
The word comes from the Latin confidentialis, meaning "of or relating to confidence," which entered English through French before gaining its current suffix -ity to form a noun. This shift allowed it to describe the state of being kept secret rather than just possessing personal trust.