1 Of an animal, esp a horse or steer: to shy, start, behave skittishly.
1893 Shands MS Speech 70, Booger. . . The word is used also, by illiterate whites, as a verb, meaning to shy, to get slightly frightened, and is said of a horse. 1896 DN 1.413 swNC, Booger . . : to shy, be frightened. “That horse boogers a little at pigs.” 1905 DN 3.71 nwAR, Booger. . . ‘He boogers.’ Used of a skittish horse. Rare. 1929 Dobie Vaquero 253 TX, For some time they “boogered” at every chance sight or sound. 1952 Brown NC Folkl. 1.521, Booger at. . . To start at from fright(?). “The horse kinda boogered at him.”—Central and east. Rare. 1966 DARE FW Addit swNM, They “boogered” or “cowboyed”—of cattle; to raise a ruckus when scared. 1969 Green Wild Cow Tales 226 TX (as of 1930s), The night the steers boogered they didn’t see me and I didn’t think that they had quite figured out where I was. 1977 in 2016 (acc) Lexis–Nexis Legal Research State Case Law: TX (Internet), Mr. Farley said he [=a horse] . . would “booger” at such things as a rabbit, or bicycle, or vehicle. 1993 Seguin Gaz.–Enterprise (TX) 29 Sept 3/2, Cows boogered at the spot forever, it seemed. 2008 in 2016 DARE File—Internet NM, The other day i stepped on him and trotted about 2 hundred yards and he boogered at somthing and i almost fell off of him as i was watching my dogs that were holding up a bull i was after. 2015 Ibid cnMA, Sirius, however, is so “in tune” with his rider that when I would relax, so would he. He boogered at stuff once or twice until I got into my own rhythm . . and that was the end of it. 2016 Ibid cTX, The horse I was riding boogered at something and bucked me off.
2 To cause to shy away; to frighten, spook; hence ppl adj boogered frightened, spooked, adj boogering frightening.
1931 TX Folkl. Soc. Pub. 9.38, They wanted to know what kind of dope I’d taken to get such a boogering nightmare as all that. 1936 Martin Tie-Fast 199, He groaned again when the great wall of water caught up with the boogered steers. One minute they were scampering madly across the rocks between the high banks. The next there was nothing but churning muddy water filled with grinding logs and spraying foam. 1944 Lubbock Avalanche–Jrl. (TX) 6 Feb /4 (newspaperarchive.com), He . . was dissuaded from attempts to steal a farmer’s car when the farmer ran out on his porch and shot at him, walked a quarter-mile southeastward and then turned directly westward when “boogered” by lights of an approaching automobile. 1947 Amarillo Globe (TX) 20 May 1/4, Rather than try to rope the zebu, Mr. Parsley boogered him a little. The bull took off in a beeline for the southeast side of the park. 1969 DARE Tape TX70, They [=horses] ’d maybe run halfway around the track, and something would booger [ˈbᴜgər] ’em, and they’d turn and pitch back the other way. 1970 DARE (Qu. GG24, Other words meaning to frighten: “Now don’t let those fellows _____you.”) Inf TX80, Get you boogered. 1979 Clovis News–Jrl. (NM) 15 Feb 2/4, Next they brought in police mounted on horses. . . The farmers just threw up their hands and boogered the horses. 2011 in 2016 DARE File—Internet nwAR, I could go out and find my own bird [=a turkey] to work at the drop of a hat, and if I boogered him, I could just as easily go find another one. 2015 Ibid OK, So, if I had a horse like your[s] that was already boogered by a swinging rope, I would start out with a long, tiring ride and then follow a rider swinging a rope all of the way home.