1911 Encyclopædia Britannica/Bronco
BRONCO, usually incorrectly spelt Broncho (a Spanish word meaning rough, rude), an unbroken or untamed horse, especially in the United States, a mustang; the word entered America by way of Mexico.
See also Bronco on Wikipedia; bronco on Wiktionary; and our 1911 Encyclopædia Britannica disclaimer.
BRONCO, usually incorrectly spelt Broncho (a Spanish word meaning rough, rude), an unbroken or untamed horse, especially in the United States, a mustang; the word entered America by way of Mexico.