What is a brief special appearance by a celebrity in a film called?

A cameo, in the context of film and television, is a brief appearance or role performed by a well-known actor or celebrity. This appearance can often be uncredited and is usually unexpected, adding an element of surprise to the narrative. The role is often minor, but its significance lies in the recognition factor and the impact it has on the audience. Cameos can be performed by actors playing themselves or in character, and they are typically used to enhance the viewer experience or add a certain flavor to the storyline.

Source: Studio Binder