Green’s Dictionary of Slang

(US campus) a trick, a prank, a hoax.

1970		Current Sl. V:3 4: Boress, n. A practical joke.
1970		D. Wakefield Going All the Way 217: It was some kind of borass Gunner was pulling, a stunt to shake people up or something.
1989		J. Morton Lowspeak 29: Boracic – a tall story, as in ‘Don’t come the boracic with me’.