The English word “buckaroo” for cowboy is a corrupt form of the Spanish word “vaquero.”
The name fits, because Anglo cowboys learned a lot of their trade from Mexican Americans, who were experts in western-style ranching long before the Anglos arrived.
Many of the cowboy techniques, equipment, and apparel we think of as distinctively American were actually copied from Latinos. The western saddle, chaps (or leather trousers), wide-brimmed hats to shield the face from the sun, the practices of rounding up and roping cattle on horseback, all these began with Mexican vaqueros.
Many western words come from Spanish, including rodeo, lariat, lasso, mustang, and chaparral.