(music) Music that is played as a background to a film, television programme, video game, etc.

Minor items, not further defined. Incidental expense. / Something that is incidental.

Loosely associated; of limited relevance except indirectly; only accidentally related. / Existing tangentially, being a byproduct, a tangent, or a likely consequence. / Occurring by chance.

(medicine) A mass lesion discovered incidentally on radiologic examination.

(manner) In an incidental manner; not of central or critical importance. / By chance; in an unplanned way. / (speech act, conjunctive) Parenthetically, by the way.

A minor expense incurred in the course of an activity.

plural of incidentaloma

Quality of being incidental.