Green’s Dictionary of Slang

bull! excl.

abbr. of bullshit! excl.

1914		T.A. Dorgan Indoor Sports 13 May [synd. cartoon] Sympathetic bull. He wishes both eyes got it [i.e. blackened].
1924		P. Marks Plastic Age 198: Nu Delta, the perfect brotherhood! Bull!
1933		M. Marshall Tramp-Royal on the Toby 78: ‘Bull!’ was my not altogether polite criticism of this long-winded discourse.
1953		Kramer & Karr Teen-Age Gangs 35: Aw, bull!
1964		N.B. Harvey Any Old Dollars, Mister? 128: ‘Bull!’ I answered, and we laughed flat out.
1970		E. Thompson A Garden of Sand (1981) 45: Aw, bull! That don’t matter. [Ibid.] 303: ‘What’s your name?’ ‘Jack.’ ‘No bull! Hey! So’s mine.’.
1982		P. Theroux London Embassy 75: Bull! It’s precisely in that category.
1983		War: A Commentary [KCTS-TV] Bull! Bullhockey! [HDAS].
1996		Penguin Bk of More Aus. Jokes 449: ‘Bull,’ said the bloke from the city. ‘I don’t believe a word of it.’.
1997		C. Hiaasen Lucky You 120: The girl chatted up all her customers. ‘Bull,’ Chubb said. ‘See how she looks at me?’.
1999		W. Coleman in Geronimo 2:6 June 🌐 Bull! Bull! Having money is not synonymous with having power in this country given the nature of racism. That’s bullcorn!