accidental
Americanadjective
-
happening by chance or accident; not planned; unexpected.
an accidental meeting.
- Synonyms:
- unintentional
-
nonessential; incidental; subsidiary.
accidental benefits.
-
Music. relating to or indicating sharps, flats, or naturals.
noun
-
a nonessential or subsidiary circumstance, characteristic, or feature.
-
Music. a sign placed before a note indicating a chromatic alteration of its pitch.
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
Usage
What does accidental mean? Accidental describes something that happens by chance or without planning, as in The hero has an accidental meeting with the villain early in the movie that sets the hero on his course. Accidental can also sometimes refer to something that comes about by chance. Example: We had to sign a contract saying we are aware of the possibility of accidental injury.
Synonym Usage
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.
Other Word Forms
Derived Forms
Etymology
Origin of accidental
First recorded in 1350–1400; Middle English word from Medieval Latin word accidentālis. See accident, -al 1
Explanation
Anything accidental happens by chance or unintentionally. People don't mean to do accidental things. An accident is something unforeseen that no one wanted to happen, like a car accident or getting hit by lightning. You can describe anything like that as accidental. Bumping into a stranger could be accidental. Forgetting to pay a bill is accidental. This word covers all the things that no one really meant or planned to happen. There are a lot of accidental events in the world, which is one reason insurance exists.
Vocabulary lists containing accidental
"Culture Clash"
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Music - High School
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Florida's B.E.S.T. Common Suffixes: -al, -ial
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Co-lead author Dr. Anthony Clarke, from the Timescales of Minerals Systems Group within Curtin's School of Earth and Planetary Sciences, said the evidence indicates the stone's movement was intentional rather than accidental.
From Science Daily • Jun. 9, 2026
They added that the coils are rigid and don’t sag over time like single-strand wires, “which helps reduce the risk of accidental wildlife entanglement.”
From Los Angeles Times • Jun. 3, 2026
Recent figures from the National Water Safety Forum show there were 202 accidental water-related fatalities across the UK in 2025.
From BBC • May 31, 2026
“In this scenario, I am the ‘other’ sibling, and although it was purely accidental, that didn’t make it hurt any less,” she wrote.
From MarketWatch • May 29, 2026
The difference was, Stef’s mom’s death was accidental.
From "Adrift" by Paul Griffin
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
