1.-insidental is incorrectly written, and should be written as "incidental" being its meaning:
insidental = incidentalincidental adj.1 applies to the circumstance or event that happens in an unexpected manner and may affect the development of a subject or business, even if it does not form part of it: the incidental one engine fault did not prevent the aterrizaje.2 of minor or non-essential:
2.-insidental = Incidentalmusica incidental or incidental music is the music that accompanies a play, a television show, a radio program, a film, a video game and other forms that are not in principle music. The term is less frequently applied to film music, because it is called more often film music or soundtrack.
3.-insidental = incidentalincidental adj. That it happens on any issue and is related to: the influenza of the girl was one of the incidental facts of the holiday. Minor: