Incidental
Incidental , adjective
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 , noun
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. — Pope