incidental

incidental — adjective

1. Connected with a more important matter or activity but not as significant or ess

1.adjectiveB2
Definition

Connected with a more important matter or activity but not as significant or essential as it is.

Example

Ignacio explained that the delivery date was incidental to the overall project schedule.

incidental + to + noun phrase for secondary importance

The committee agreed that the seating arrangement was an incidental detail.

attributive position: incidental detail / incidental matter

Common collocations
  • incidental to
  • incidental detail
  • incidental matter
  • incidental issue
  • incidental cost
Synonyms
  • secondary

    More common in everyday use; implies coming after the most important thing in rank.

  • minor

    Emphasises small size or degree rather than the relationship between two things.

  • subordinate

    More formal; stresses being placed in a lower rank or position.

Antonyms
  • essential

    Absolutely necessary rather than secondary.

  • primary

    First in importance, the opposite of secondary.

Grammar Patterns

be incidental + to + noun phrase

Usage Note

Often followed by the preposition 'to': X is incidental to Y means X is far less important than Y.

Common Mistakes

The packaging cost was accidental to the main budget.
The packaging cost was incidental to the main budget.
'accidental' means happening by chance; 'incidental' means less important or secondary.

2. Occurring alongside a more important event or activity and arising naturally fro

2.adjectiveB2
Definition

Occurring alongside a more important event or activity and arising naturally from it.

Example

Noa budgeted for incidental travel costs such as taxi fares and meals.

incidental + noun for resulting expenses

The new safety rules brought incidental changes to the way the factory operated.

Common collocations
  • incidental costs
  • incidental expenses
  • incidental effects
  • incidental changes
  • incidental to
Synonyms
  • accompanying

    Neutral; simply describes things that go together without implying importance.

  • associated

    Broader; can describe any link, not just things that co-occur.

  • consequent

    More formal; stresses the cause-and-effect relationship.

Antonyms

Grammar Patterns

incidental + noun

Usage Note

Unlike sense 1 (LESS IMPORTANT), this sense does not emphasise the low importance of the thing — rather it focuses on the fact that one thing accompanies another. Frequently used in attributive position: 'incidental costs', 'incidental effects'.

Common Mistakes

These side effects are accidental to the treatment.
These side effects are incidental to the treatment.
'accidental' means unplanned by chance; 'incidental' means happening as a natural accompaniment.

3. Happening by chance rather than as a result of a plan or intention.

3.adjectiveC1
Definition

Happening by chance rather than as a result of a plan or intention.

Example

Jude and his former teacher met at the art gallery by pure incidental chance.

purely / entirely incidental for 'by chance' meaning

The discovery of the old coins was incidental to the archaeological dig for Roman pottery.

Common collocations
  • purely incidental
  • entirely incidental
  • not ... incidental
  • incidental discovery
  • incidental meeting
Synonyms
  • accidental

    More common; implies the event was not meant to happen, sometimes with a negative tone.

  • unintentional

    Focuses on the lack of intention rather than on chance.

  • fortuitous

    Often carries a positive tone — a lucky chance.

Antonyms

Grammar Patterns

purely/entirely incidental

not ... incidental

Usage Note

Distinguish from sense 1 (LESS IMPORTANT) where the focus is on low significance, and sense 2 (ACCOMPANYING) where the focus is on natural co-occurrence. This sense focuses purely on the absence of planning or intention. Commonly modified by adverbs like 'purely' or 'entirely'.

Common Mistakes

The extra costs were incidental — they were listed in the contract from the start.
The extra costs were incidental
they were not part of the original plan.' — If something was planned from the start, it is not 'incidental' in the by-chance sense.

incidental — noun

Word family

Synonym discussion

Sense: adjective/1

All four words describe something that ranks below the most important thing, but they differ in what they emphasise. Secondary most directly describes position in a sequence or rank: 'the secondary goal' comes after the primary one. Minor focuses on scale or degree — a minor injury is small, but it may still be directly important to the person affected. Subordinate stresses a relationship of dependency or hierarchical control, such as a subordinate role in an organisation. Incidental adds the idea of being connected to something else without being essential to it; an incidental cost is secondary in importance AND arises naturally from the main activity. In everyday speech, secondary and minor are more common; subordinate is formal; incidental is used when the connection between two things matters as much as the difference in importance. For example, 'a minor detail' could be small but still part of the plan, whereas 'an incidental detail' is something that came along with the main plan without being central to it.

incidental ↗secondary ↗minor ↗subordinate ↗

Common collocations

Nouns

Adverbs

Phrases

  • incidental to the main issue
  • purely incidental
  • incidental costs and expenses

Prepositions

Etymology

LatinFrenchEnglish

The word 'incidental' comes from the noun 'incident', which traces back through French to Latin 'incidere', meaning 'to fall upon' or 'to happen'. The '-al' suffix turns the noun into an adjective. Originally, 'incidental' described things that 'fell upon' or happened alongside a main event. By the 1600s it had developed its modern meaning of something less important that accompanies something else. The noun form (plural 'incidentals') emerged in the 1800s, mainly in financial contexts for unplanned expenses.