Search

happening by chance or ; 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.
Contemporary Examples

On her first episode live from New York, she accidentally said the f-word.
The Casual Genius of Jenny Slate: ‘Marcel the Shell,’ ‘Obvious Child,’ and the Ghost of ‘SNL’ Kevin Fallon October 16, 2014

Watch her strip down to the point of embarrassment, accidentally revealing her “nana,” unaware of how much she was taking off.
Most Outrageous ‘Jersey Shore’ Moments Sadie Bass August 2, 2011

Karim El-Hamdi remembers vividly how he accidentally became a human trafficker.
Confessions of a Human Trafficker Who Smuggled Desperate Migrants Into Europe Barbie Latza Nadeau June 4, 2014

Beck had accidentally destroyed hours of urgently needed American reports.
The Intern Who Birthed The KAL007 Conspiracy Theories Tim Mak September 7, 2014

Someone had accidentally turned on the device hours beforehand, and by the time the meeting started, the batteries were dead.
Mohamed Mohamud Trial: Was He Tricked Into Terrorism? Winston Ross April 22, 2012

Historical Examples

She had not tried at all; the whole thing had come about accidentally.
The New Warden Mrs. David G. Ritchie

He said he was out hunting with a friend, and his friend’s gun went off accidentally.
Brave and Bold Horatio Alger

They have some dangerous project brewing I am well satisfied, from circumstances which accidentally fell under my own observation.
The Cavaliers of Virginia, vol. 1 of 2 William A. Caruthers

When accidentally struck by the janitor’s broom, he gives off a cloud of dust.
The Devil’s Dictionary Ambrose Bierce

In doing this, however, he once accidentally stumbled, and spoke of Mrs. Devarges as “Grace Conroy.”
Gabriel Conroy Bert Harte

adjective
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
noun
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
adv.

late 14c., “non-essentially,” also “unnaturally,” from accidental + -ly (2). Meaning “unintentionally” is recorded from 1580s; phrase accidentally on purpose is recorded from 1862.
adj.

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.
n.

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