What does accidental mean?
Accidental describes something that happens by chance rather than by design — an outcome no one intended, planned, or foresaw. It applies most often to events, actions, and discoveries: an accidental meeting, an accidental slip of the tongue, an accidental breakthrough in the laboratory. The word carries no strong judgment of blame; it simply signals the absence of intent, which makes it useful in contexts ranging from casual conversation to formal legal language, where phrases like "accidental death" have precise technical meanings. In music, accidental also functions as a noun, naming the sharp, flat, or natural sign that temporarily alters a note's pitch outside the key signature. Derived from the Latin "accidere," meaning "to happen" or "to befall," the word shares deep roots with "accident," "incident," and "cadence." Its opposite is deliberate or intentional, and its common adverbial form is "accidentally."
Happening by chance or without intention; not planned or deliberate.
"Their accidental encounter at the airport led to a lifelong friendship."
In legal and insurance contexts, "accidental" has a stricter technical sense, denoting events that are both unforeseen and unintended.
In music, a sign — a sharp, flat, or natural — placed before a note to raise or lower its pitch by a semitone, or to cancel a previous alteration.
"The composer marked the passage with several accidentals to create an unexpected harmonic shift."
This sense is used primarily by musicians; the plural is "accidentals."
The plural applies only to the musical noun sense, referring to multiple sharp, flat, or natural signs.
"The score was dense with accidentals, reflecting the piece's chromatic style."
Every accidental in music — every sharp, flat, and natural on the page — descends from the same Latin root as the word "cadence": things that simply fall out as they will.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of accidental
Accidental derives from the Latin verb "accidere," meaning "to happen" or "to befall," formed from "ad-" (toward) plus "cadere" (to fall) — literally, something that falls out or occurs. It entered English via Late Latin "accidentalis" and Old French, appearing in English usage from the late medieval period onward, with its familiar modern sense of "happening by chance" well established by the early modern era. The same Latin root "cadere" gives us cognates including "accident," "incident," "cadence," and "cadenza," all carrying some notion of falling, happening, or occurring.
Related word forms
How accidental is actually used
Common across all registers, from everyday conversation to legal contexts (e.g., "accidental death"). In insurance and law, "accidental" carries a precise technical meaning requiring the event to be unforeseen and unintended. In music, the noun form is standard among musicians, while the general public more often encounters only the adjectival sense.
Easily confused with accidental
"Incidental" means occurring as a minor or secondary consequence of something else, while "accidental" means happening purely by chance and without intention.