unison

Etymology

It is inherited from Middle English unisoun,^[2] borrowed from Middle French unison, now unisson,^[3][2][4][5] and directly borrowed from Medieval Latin ūnisonus (“having one sound, sounding the same”),^[3][5][2][6] from Late Latin ūnisonus (“in immediate sequence in the scale; monotonous”),^[2][7][5] a compound of ūni- (“one”), from ūnus, and sonus (“sound”).^[3][8][7][5] The two Latin parts go back to Proto-Indo-European *oi-no- (“one”) and Proto-Indo-European *swen- (“to sound”).^[5][7] The Latin adjective is recorded from the 6th century, in Boethius, and as a noun for identity in pitch from the 13th century in British sources;^[3] the French noun dates from 1374–76.^[3] Etymonline gives the Late Latin form as ūnisonius.^[5] Related words in the other Romance languages are Catalan uníson, Spanish unísono, Portuguese unissono and Italian unisono.^[3][9]

Earliest recorded meaning

A tone of the same pitch as another: 1410, as unisoun, in Barnhart.^[2] The OED's first quotations, for identity in pitch and for a note of the same pitch as another, are from musical treatises of before 1450,^[3] and Etymonline dates the word to the mid-15th century.^[5]

Semantic evolution

Unison began as a term of music, "of the same sound".^[8] Early on it named the identity in pitch of two notes, regarded as an interval, and a note of the same pitch as another;^[3] Etymonline adds the interval of an octave.^[5] From 1603 it was an accompanying melody sung or played at the same pitch or octaves apart.^[3] The figurative sense of agreement or harmony came in the 17th century:^[8] the OED records it from 1606, after a now obsolete sense of a thing that agrees perfectly with another (1594–1876),^[3] while Etymonline dates it to the 1640s and Barnhart to 1650.^[5][2] The adjective, "sounding together", is recorded from 1582 and "identical in pitch" from 1598;^[3] its figurative sense "in complete agreement" (1649) is now rare.^[3][6] Johnson (1755) defined the noun first as a string that has the same sound as another, and quoted Milton for the adjective.^[10]

Timeline

• 1410 – unisoun, a tone of the same pitch as another.^[2]
• before 1450 – identity in pitch of two or more notes; a note of the same pitch as another.^[3]
• 1582 – adjective, sounding together.^[3]
• 1594 – a thing in perfect agreement with another (obsolete by 1876).^[3]
• 1603 – an accompaniment at the same pitch or octaves apart.^[3]
• 1606 – exact agreement, concord, harmony.^[3] Barnhart dates this sense 1650.^[2]
• 1609 – a single unvaried tone, a monotone (obsolete by 1742).^[3]
• 1619 – a united, unanimous declaration.^[3]
• 1649 – adjective, in complete agreement.^[3][6]

Meanings

Noun

1. In music, sameness of pitch between two or more notes; the interval between two notes of the same pitch.^[11][6][3]
2. The singing or playing of the same notes by several voices or instruments at once, at the same pitch or octaves apart.^[6][3]
3. Complete agreement; harmony or concord.^[11][6][3]
4. in unison: all together, at the same time, or in agreement: The crowd chanted in unison.^[11][6][3]

Adjective

1. Sung or played at the same pitch or in octaves: a unison chorus.^[11][6][3]
2. (archaic) In agreement; concordant.^[6][3]

Word family

• nonunison
• unisonous

Related words

• union
• unity
• sound
• sonorous

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
3. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
4. ^ 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 e f g h i Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ a b c Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
9. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
10. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
11. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins