buck·a·roo also buck·er·oo (bŭk'ə-rōō') n.
pl.buck·a·roos or buck·er·oos Western U.S. See cowboy.
[Alteration (perhaps influenced by buck1) of Spanish vaquero, from vaca, cow, from Latin vacca.]
cow·boy (kou'boi') n.
A hired man, especially in the western United States, who tends cattle and performs many of his duties on horseback. Also called cowman, cowpoke, cowpuncher; also called regionally buckaroo, vaquero, waddy2. See Regional Note at vaquero.
An adventurous hero.
Slang A reckless person, such as a driver, pilot, or manager, who ignores potential risks.