incidental (n.)
- accessory
- acciaccatura
- accident
- accidental
- addendum
- addition
- adjunct
- ado
- appendage
- appoggiatura
- appurtenance
- arabesque
- article
- aspect
- auxiliary
- cadence
- cadenza
- case
- chance
- chancy
- collateral
- coloratura
- contingency
- contingent
- count
- current
- datum
- detail
- division
- doing
- element
- embellishment
- extra
- facet
- fact
- factor
- flight
- flourish
- grace
- happening
- happenstance
- iffy
- inessential
- instance
- item
- matter
- minor
- minutia
- nonessential
- odd
- off
- on
- ornament
- other
- parenthetical
- particular
- passage
- passing
- petty
- point
- regard
- respect
- resultant
- roulade
- run
- secondary
- side
- spare
- subordinate
- subsidiary
- supplement
- thing
- trifling
- turn
incidental (adj.)
- accessory
- accidental
- accompanying
- additional
- adjunct
- ado
- adrift
- adscititious
- adventitious
- afloat
- afoot
- aleatory
- ancillary
- appurtenant
- auxiliary
- case
- casual
- causeless
- chance
- chancy
- circumstantial
- collateral
- conditional
- contingent
- count
- current
- dicey
- extra
- extraneous
- extrinsic
- fact
- fatal
- flight
- fluky
- fortuitous
- haphazard
- iffy
- immaterial
- impertinent
- inadmissible
- inapplicable
- inapposite
- inappropriate
- inconsequent
- inconsequential
- indeterminate
- inessential
- insignificant
- irrelevant
- item
- lesser
- minor
- negligible
- nonessential
- occasional
- occurring
- odd
- off
- on
- ongoing
- other
- out-of-the-way
- paltry
- parenthetical
- part-time
- particular
- passing
- petty
- point
- prevailing
- prevalent
- provisional
- random
- resultant
- risky
- run
- secondary
- serendipitous
- side
- spare
- subordinate
- subsidiary
- superfluous
- supplemental
- supplementary
- thing
- trifling
- trivial
- turn
- uncaused
- undetermined
- unessential
- unexpected
- unforeseeable
- unforeseen
- unimportant
- unlooked-for
- unplanned
- unpredictable
