bronco

Etymology

It is borrowed from Spanish bronco, a noun use in American Spanish of the adjective bronco, said of a horse that is untamed or not broken in (from 1757 in the phrase caballo bronco).^[2][3][4][1] Collins and Dictionary.com take it as short for potro bronco (“untamed colt”).^[5][6] In Spanish the adjective meant rough, gruff or harsh (1490), and was first a noun meaning a log or a knot in wood.^[2][3][7] It is apparently from Vulgar Latin *bruncus (“knot, projection”),^[2][7][8][4] which Barnhart, following Corominas, Etymonline and Klein take as a blend of Latin broccus (“projecting”) and truncus (“trunk of a tree”).^[3][7][9][2] The Latin form is also the source of Italian bronco (“stub of a branch”) and Old Occitan bronc (“projection, roughness”).^[4][10] Weekley thought the Spanish word of unknown origin,^[11] and Partridge took broccus as perhaps Celtic.^[12]

Earliest recorded meaning

An untamed or half-tamed horse of the American Southwest: 1850, in American English, according to Merriam-Webster, Etymonline and Barnhart, who calls the date probable;^[4][7][3] the OED, revised in 2025, has its first example from 1861, in J. R. Browne's Coast Rangers in Harper's.^[2]

Semantic evolution

The adjective bronco, wild or mean, followed in 1866 in New Mexico,^[2][13][14] and Dictionary.com dates the noun to 1865–70, as an Americanism.^[6] The noun was later used of a horse inclined to buck, and in a wider way of any range horse.^[2][4][13] The bronco-buster, a man who breaks horses, appears in 1886,^[7] and the clipped form bronc in 1893.^[4][13] In 20th-century American slang a bronco was also a spy for safe-breakers (1926) and a young man new to the homosexual world (1933).^[14]

Timeline

• 1850 – an untamed or half-tamed horse of the western United States.^[4][7][3] The OED's first example is from 1861.^[2]
• 1866 – adjective, wild, uncontrollable, rough.^[2][13][14]
• 1926 – slang, a spy for safe-breakers.^[14]
• 1933 – slang, a young man new to homosexual practices.^[14]

Meanings

Noun

1. A wild or partly tamed horse or pony of the western plains of North America; a mustang.^[5][8][4][2]
2. A horse that is hard to break or trained to buck, as in a rodeo.^[4][2][13]

Adjective

1. (US) Wild, uncontrollable or rough.^[2][13][14]

Word family

• broncobuster

Related words

• bronc
• broach
• trunk

Usage notes

The spelling broncho is less common;^[4][5][7] Partridge thought bronco the better form.^[12]

References

1. ^ a b c Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c d e f g h i j Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
9. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
10. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
11. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
12. ^ a b Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
13. ^ a b c d e f Cassidy, Frederic G. & Joan Houston Hall (eds.) (1985–2002), Dictionary of American Regional English, vols I–IV, Cambridge, Mass.: Belknap Press of Harvard University Press
14. ^ a b c d e f Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com