Green’s Dictionary of Slang

1. a cowboy or cattle-driver; also as v.

1827		Dewees Letter from Texas 66: A few wealthy rancheros [...] are surrounded by ten or fifteen families of poor people, who reside near them, together with peons and bakharas, or herdsmen.
1913		B.T. Harvey ‘Word-List From The Northwest’ in DN IV:i 26: buckaroo, n. A broncho buster, cowpuncher, cowboy. [...] ‘That night the buckaroos shot up the town.’.
1920–23		in J.M. Hunter Trail Drivers of Texas (1963) I 331: A cowboy is a ‘waddy’ or ‘screw’ or ‘buckaroo’.
1924		Davies Skyline Trail 15: The buckaroo [...] takes his fall, but, after all, bends the broncho’s will to his own [DA].
a.1932		‘Wild Buckaroo’ in G. Logsdon Whorehouse Bells Were Ringing (1995) 106: I’m a high lopin’ cowboy and a wild buckaroo.
1936		R.F. Adams Cowboy Lingo 22: The terms ‘baquero,’ ‘buckhara,’ and ‘buckayro,’ [...] were also used.
1938		B. Conlon ‘Rope Meat’ in Wild West Weekly 22 Oct. 🌐 A big buckaroo with a shock of yellow hair.
1947		W.D. Overholser Buckaroo’s Code (1948) 8: Buckaroos drink together. [Ibid.] 103: He’s a long drink of water that used to buckaroo for Malloy.
1948		Popular Western June 28/1: Local buckaroos competed with world champion riders and ropers [DA].
1951		in Randolph & Legman Ozark Folksongs and Folklore (1992) II 652: That’s one thing I can do, / I’m a second-rate pimp, but a good buckaroo.
1963		A.E. Farrell Vengeance 67: ‘What the hell has it got to do with us?’ demanded Fireson angrily. ‘Quite a ruddy lot, me bold buckaroo, hasn’t it, George?’.
a.1969		‘Red Wing’ in G. Logsdon Whorehouse Bells Were Ringing (1995) 209: There once lived an Indian maid, / She sat in the silent shade, / Afraid some buckaroo would ram it up her flue.
1972		D. Dalby ‘African Element in Amer. Eng.’ in Kochman Rappin’ and Stylin’ Out 178: buckaroo, bucker—‘cowboy’.
1994		Mountain Democrat (Placerville, CA) 26 Jan. 5/1: Scutte is first and foremost, truly a northern Nevada buckaroo.

2. attrib. use of sense 1.

1972		B. Hannah Geronimo Rex 256: I’ll lay some kind of dent in that buckaroo hat for him.
1999		Guardian Guide 26 June–2 July 54: Likeable buckaroo-ish comedy with a trio of [...] middle-class men heading west to rediscover themselves on a cattle-drive holiday.

3. a lively young man.

1920		Appleton (WI) Daily Post 6 Jan. 5/6–7: [advert] Buckaroo (buck-a-roo) [...] Meaning, when applied to the masculine gender of the human species, a lively young buck. 2. A gay dog.
1986		S. King It (1987) 326: Is that yer name or yer address, buckaroo?

4. a man, a fellow.

1931		R.E. Howard ‘Texas Fists’ Fight Stories May 🌐 Them miners has got the fightin’est buckaroo in these parts.
1983		C. Heath A-Team 2 (1984) 91: You and your three buckaroos.
1989		(con. 1968) W.E. Merritt Where the Rivers Ran Backward 243: You’ll know this buckaroo caught himself the frostbite in this tropical fuckin’ country.

5. (Aus./N.Z.) a farmhand.

1946

P.L. Soljak N.Z. 115: Colloquialisms common to New Zealand and Australian English [...] buckaroo: farmhand.