From incident +‎ -al.

• IPA^(key): /ɪnsɪˈdɛntəl/, /ɪnsəˈdɛntəl/
  • (US) IPA^(key): (nasal flap) [ɪnsɪˈdɛ.ɾ̃əl], (enunciated) [ɪnsɪˈdɛn.tʰəl]

    • Audio (US, enunciated):

      (file)

    • Audio (US, more common realization):

      (file)

incidental (comparative more incidental, superlative most incidental)

1. Loosely associated; of limited relevance except indirectly; only accidentally related.

   That character, though colorful, is incidental to the overall plot.

   incidental evidence

2. Existing tangentially, being a byproduct, a tangent, or a likely consequence.

   Injuries are incidental to contact sports: they're going to happen.

3. Occurring by chance.
4. (physics, of radiation) Entering or approaching, prior to reflection (more frequently incident).

• (existing as an accident): accidental, contingent; See also Thesaurus:circumstantial
• (occurring by chance): accidental, serendipitous; See also Thesaurus:accidental

• (antonym(s) of “existing as an accident”): inevitable, necessary, impossible; See also Thesaurus:inevitable
• (antonym(s) of “occurring by chance”): inevitable, intentional; See also Thesaurus:intentional

• incident
• incidence

incidental (plural incidentals)

1. Minor items, not further defined. Incidental expense.

   She's costing us a lot in incidentals.

2. Something that is incidental.

• anticlined

• Rhymes: -al, -aw
• Hyphenation: in‧ci‧den‧tal

incidental m or f (plural incidentais)

1. incidental (existing by chance)

• incidentalmente

• “incidental”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Borrowed from French incidentel.

incidental m or n (feminine singular incidentală, masculine plural incidentali, feminine/neuter plural incidentale)

1. incidental

• IPA^(key): /inθidenˈtal/ [ĩn̟.θi.ð̞ẽn̪ˈt̪al] (Equatorial Guinea, Spain)
• IPA^(key): /insidenˈtal/ [ĩn.si.ð̞ẽn̪ˈt̪al] (Latin America, Philippines)
• Rhymes: -al
• Syllabification: in‧ci‧den‧tal

incidental m or f (masculine and feminine plural incidentales)

1. incidental (existing by chance)

• “incidental”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025