incidental

Incidental is an adjective meaning occurring as a minor accompaniment or supplementary to something more important; not essential in itself. It describes relations or items that accompany a primary object or activity rather than defining it. Common uses include incidental music, incidental expenses, and incidental findings, each indicating a secondary or accompanying aspect.

Etymology: The term derives from Latin incidentalem, from incidere "to fall upon," via late Latin into English. It has long been used to mark things connected to a primary matter but not central to it.

In the performing arts, incidental music refers to music written to accompany a play, film, or other dramatic work. It sets mood, signals transitions, and supports scenes but is not the main, stand-alone score. The concept was especially influential in 18th–19th century theatre and remains in use in modern productions and media.

In medicine, incidental findings are results discovered unintentionally during routine imaging or examination for another purpose, which may require follow-up to determine significance. In business and law, incidental expenses are minor costs tied to a project, and incidental damages or costs are those arising as a secondary consequence of a primary breach or action.

Usage: Incidental is often paired with phrases like incidental to, indicating a secondary or accompanying relationship rather than central importance.