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.
- Occurring or likely to occur as an unpredictable or minor accompaniment: the snags incidental to a changeover in upper management. See Synonyms at accidental.
- Of a minor, casual, or subordinate nature: incidental expenses.
- A minor accompanying item or expense: a pocket in the suitcase for incidentals.