Incidental /(?)/

In·ci·den·tal

Incidental

a.
  1. Happening, as an occasional event, without regularity; coming without design; casual; accidental; hence, not of prime concern; subordinate; collateral; as, an incidental conversation; an incidental occurrence; incidental expenses.
    By some, religious duties . . . appear to be regarded . . . as an incidental business.
    I treat either or incidentally of colors.

Incidental

n.
  1. An incident; that which is incidental; esp., in the plural, an aggregate of subordinate or incidental items not particularized; as, the expense of tuition and incidentals.