happening or likely to happen in an unplanned or subordinate conjunction with something else.
incurred casually and in addition to the regular or main amount: incidental expenses.
likely to happen or naturally appertaining (usually followed by to).


something incidental, as a circumstance.
incidentals, minor expenses.

Origin of incidental

First recorded in 1610–20; incident + -al1
Related formsin·ci·den·tal·ness, nounnon·in·ci·den·tal, adjectivenon·in·ci·den·tal·ly, adverbun·in·ci·den·tal, adjectiveun·in·ci·den·tal·ly, adverb
Can be confusedincidence incidents incidental

Synonyms for incidental

Antonyms for incidental Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for incidental

Contemporary Examples of incidental

Historical Examples of incidental

  • And Mr. Price said that though folly was incidental to Alfred's years, it must be checked.

  • "Cousin Amelia is only incidental," Jan said, when they were all three seated in the balcony.

    Jan and Her Job

    L. Allen Harker

  • "There are sure to be incidental expenses," said Philip cautiously.

  • The club and Bobby were incidental points of contact, pleasant, but not permanent.

    The Dominant Strain

    Anna Chapin Ray

  • The production of gold is only incidental, as it were, while the output of silver might be doubled.

    Aztec Land

    Maturin M. Ballou

British Dictionary definitions for incidental



happening in connection with or resulting from something more important; casual or fortuitous
(postpositive foll by to) found in connection (with); related (to)
(postpositive foll by upon) caused (by)
occasional or minorincidental expenses


(often plural) an incidental or minor expense, event, or action
Derived Formsincidentalness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for incidental

"casual, occasional," 1610s, from Medieval Latin incidentalis, from incidens (see incident (n.)). Incidentals (n.) "'occasional' expenses, etc.," is attested by 1707.

Online Etymology Dictionary, © 2010 Douglas Harper