n. An incident; that which is incidental; esp., in the plural, an aggregate of subordinate or incidental items not particularized;
a. Happening, as an occasional event, without regularity; coming without design; casual; accidental; hence, not of prime concern; subordinate; collateral;
By some, religious duties . . . appear to be regarded . . . as an incidental business. Rogers.
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I treat either or incidentally of colors. Boyle. [ 1913 Webster ]