incidental

Etymology

It is formed from English incident + -al.^[2][3][4] The Shorter Oxford says it was originally from Medieval Latin incidentalis, used in angulus incidentalis (“angle of incidence”), and in modern use formed from incident,^[5] and Etymonline and the Oxford Dictionary of English derive it from the Medieval Latin word.^[6][7] Merriam-Webster thinks its meaning was probably influenced by incidenter (“incidentally”).^[4] Incident comes from Latin incidēns (“falling upon, happening”), the present participle of incidō (“to fall upon, happen, befall”),^[6][7] formed from in- (“on”) and cadō (“to fall”), from Proto-Indo-European *kad- (“to fall”).^[6] The OED compares French incidentel.^[2] The earlier English adjective in this sense was incident, from the 1520s.^[6]

Earliest recorded meaning

Liable to happen to something, in incidental to: first recorded in 1616, in Coryat.^[2][5] The sense "occurring by chance alongside something more important" follows in 1644, in Milton's Of Education;^[2][4] Etymonline dates the word to the 1640s.^[6]

Semantic evolution

From the idea of something that falls upon or happens alongside another thing, the word came to mean casual, minor or secondary.^[6][2] Johnson (1755) defined it as happening by chance, not intended, quoting Milton.^[8] From 1740 it was used of charges and expenses that are incurred besides the main ones,^[2] and the noun incidentals, such occasional expenses, is attested from 1707.^[6][2][4] Incidental music, background music, originally in operas, dates from 1812.^[6] In the 19th century it was also used for "met with by chance" (1856) and of a person given to relating incidents (1843, Carlyle).^[2]

Timeline

• 1616 – incidental to, liable to happen to.^[2]
• 1644 – occurring by chance or as a minor accompaniment.^[2][4]
• 1707 – noun, an incidental item or expense.^[2][6][4]
• 1740 – of a charge or expense, besides the main one.^[2]
• 1812 – incidental music.^[6]
• 1876 – incidental images, afterimages.^[2]

Meanings

Adjective

1. Happening by chance or as a minor accompaniment to something more important; casual or subordinate: The film's incidental details were carefully researched.^[4][9][2]
2. Of costs, small and occasional, besides the main ones: incidental expenses.^[4][9][2]
3. incidental to: likely to happen as a consequence of, or naturally connected with: the risks incidental to deep-sea diving.^[9][2][5]
4. incidental upon: following from, caused by.^[9][2]

Noun

1. Something incidental; usually in the plural, minor items or expenses not listed separately: The fee covers tuition but not incidentals.^[4][9][2]

Word family

• incidentalness
• nonincidental
• unincidental
• incidentally
• incidental music

Related words

• incident
• incidence
• coincidental
• accident
• occasion

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
4. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b c d e f g h i j Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
8. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
9. ^ a b c d e Collins English Dictionary (2023), Glasgow: HarperCollins