keep a lid on sth

What is the origin of the idiom "keep a lid on something" and when to use it?

The origin of the idiom "keep a lid on something" stems from the literal usage of lids on containers in the late 19th/early 20th century, as it was common practice to use tight-fitting lids to prevent contents from being spilled or seen. This simple act of securing a lid came to represent concealing what was inside in a metaphorical sense, and one of the earliest figurative usages referred to keeping secrets "under wraps" with a "tight lid," which then developed into newspaper uses by the 1900s employing the phrase such as "keeping a lid on the scandal" to denote suppressing details and maintaining secrecy about a covert matter. It is commonly invoked legally to suppress unflattering evidence or privately settled allegations.

What is the origin of the idiom "keep a lid on something" and when to use it?

The idiomatic phrase "keep a lid on something" has its origins in the United States in the late 19th/early 20th century, deriving from the literal notion of securely fastening a tight-fitting lid onto a container to prevent its contents from spilling out, which then developed figuratively into referring to keeping information contained or suppressed, as evidenced by some early newspaper citations from the late 1800s discussing keeping secrets or scandals tightly guarded. It is frequently used in political, legal, and workplace settings to describe efforts to prevent damaging leaks, skeletons in the closet from being aired out, or potential scandals from emerging.