coincidental

Etymology

It is formed from English coincident + -al,^{[2][3][4][5][6]} on the model of incidental.^[2] Coincident is from French coïncident,^[2][3] from Medieval Latin coincidō (“to fall upon together”), a verb of astrology,^[3] formed from com- (“with, together”) and incidō (“to fall upon”), from in- (“upon”) and cadō (“to fall”), from Proto-Indo-European *kad- (“to fall”).^[3]

Earliest recorded meaning

Of the nature of coincidence, or simply coinciding: before 1806, in the Remains of H. K. White, published in 1807.^[2] Etymonline dates the word to about 1800 and Dictionary.com to 1790–1800,^[3][6] while Merriam-Webster Unabridged gives about 1880.^[5]

Semantic evolution

The adjective's two senses follow those of coincidence.^[2] The older is "occurring or existing at the same time", the sense of coincidence from 1650;^[2] the newer, "happening by chance, without apparent connection", follows coincidence as a notable concurrence of events with no apparent cause (from before 1682), and is recorded for the adjective from 1884.^[2] The adverb coincidentally has the same two meanings.^[4]

Timeline

• before 1806 – of the nature of coincidence; coinciding.^[2]
• 1884 – of the nature of a coincidence, happening by chance.^[2]

Meanings

Adjective

1. Happening by chance, as a coincidence, without being planned or connected: Any likeness between the two designs is purely coincidental.^[7][5][2]
2. Occurring or existing at the same time; coincident: The drought was coincidental with a fall in grain prices.^[5][2]

Word family

• coincidentally
• noncoincidental
• uncoincidental

Related words

• coincidence
• coincident
• coincide
• incidental

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ Collins English Dictionary (2023), Glasgow: HarperCollins