bit part

This term describes a role of minimal importance, often serving as atmospheric background or a brief plot device rather than a developed character. It carries a connotation of insignificance or a starting point in a professional acting career, where the performer is a functional element of the scene.

While a "cameo" is a small role played by a famous person for effect, a "bit part" is typically assigned to an unknown actor or an extra who may have a few lines. It is used primarily within the industry context of theater, film, and television to distinguish between lead, supporting, and marginal roles.