Определение и Значение "on the q.t."

What is the origin of the idiom "on the q.t." and when to use it?

The idiom "on the q.t." originated from the phrase "quiet as a cat," which was later shortened to "quiet as a QT." Over time, "QT" evolved to "q.t." and eventually became the idiom "on the q.t." It refers to keeping something secret, confidential, or discreetly hidden from others. The phrase implies a need for caution or secrecy, often suggesting that the information or activity being discussed should not be openly disclosed or shared.