happening by chance or accident; not planned; unexpected: an accidental meeting.
nonessential; incidental; subsidiary: accidental benefits.
Music. relating to or indicating sharps, flats, or naturals.


a nonessential or subsidiary circumstance, characteristic, or feature.
Music. a sign placed before a note indicating a chromatic alteration of its pitch.

Origin of accidental

First recorded in 1350–1400; Middle English word from Medieval Latin word accidentālis. See accident, -al1
Related formsac·ci·den·tal·ly, ac·ci·dent·ly, adverbac·ci·den·tal·ness, ac·ci·den·tal·i·ty, nounnon·ac·ci·den·tal, adjective, nounnon·ac·ci·den·tal·ly, adverbnon·ac·ci·den·tal·ness, nounpre·ac·ci·den·tal, adjectivepre·ac·ci·den·tal·ly, adverbpseu·do·ac·ci·den·tal, adjectivepseu·do·ac·ci·den·tal·ly, adverbqua·si-ac·ci·den·tal, adjectivequa·si-ac·ci·den·tal·ly, adverbun·ac·ci·den·tal, adjectiveun·ac·ci·den·tal·ly, adverb

Synonyms for accidental

Synonym study

1. Accidental, casual, fortuitous all describe something outside the usual course of events. Accidental implies occurring unexpectedly or by chance: an accidental blow. Casual describes a passing event of slight importance: a casual reference. Fortuitous is applied to events occurring without known cause, often of a fortunate or favorable nature: a fortuitous shower of meteors. It often also implies good luck or good fortune: a fortuitous choice leading to rapid advancement.

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

Examples from the Web for accidently

Contemporary Examples of accidently

  • An ITF anti-doping tribunal ruled in 2009 that Richard Gasquet accidently ingested cocaine while kissing a woman at a nightclub.

    The Daily Beast logo
    Tennis Has a Doping Problem

    Sujay Kumar

    July 8, 2013

  • Did you once accidently apply to a school in Michigan thinking it was in New York?

    The Daily Beast logo
    A Gifted Man’s Leading Lady

    Jace Lacob

    September 23, 2011

Historical Examples of accidently

  • At that very moment, the crepe flounce on her dress was accidently torn off.

    Revolutionary Reader

    Sophie Lee Foster

  • He had chopped off several of her fingers, when they were accidently interrupted.

    Basque Legends

    Wentworth Webster

  • The matter was settled for him by meeting her accidently outside the buvette.

    Beggars on Horseback

    F. Tennyson Jesse

  • The other accidently put an end to her own life several weeks ago.

    Little Wolf

    M. A. Cornelius

  • I was in dread for fear his trembling finger might accidently touch the trigger.

    A Texas Cow Boy

    Chas. A. Siringo

British Dictionary definitions for accidently



occurring by chance, unexpectedly, or unintentionally
nonessential; incidental
music denoting sharps, flats, or naturals that are not in the key signature of a piece
logic (of a property) not essential; contingent


an incidental, nonessential, or supplementary circumstance, factor, or attribute
music a symbol denoting a sharp, flat, or natural that is not a part of the key signature
Derived Formsaccidentally, adverb
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 accidently



late 14c., "non-essential," from Old French accidentel or directly from Medieval Latin accidentalis, from Latin accidentem (see accident). Meaning "outside the normal course of nature" is from early 15c.; that of "coming by chance" is from 1570s.



late 14c., "non-essential quality," from accidental (adj.). The musical sense is from 1868.

Online Etymology Dictionary, © 2010 Douglas Harper