An overused expression is a/an _________

An overused expression is a "cliche". A cliche is a phrase or expression that has become so overused that it has lost its original meaning or impact. It is often used as a shortcut to convey a certain idea or emotion, but it can be seen as trite or unoriginal. Examples of cliches include phrases like "at the end of the day", "all's well that ends well", or "time heals all wounds". These expressions are often used in everyday conversation, but they can become tiresome or predictable when used too frequently. In literature and writing, the use of cliches can be seen as a weakness or a lack of originality. Good writers strive to find fresh and innovative ways to express their ideas and emotions, and avoid relying on cliches as a crutch. Overall, a cliche is an overused expression that has lost its original impact and can be seen as unoriginal or trite.