look up any word, like fuck boy:
 
1.
A man who smoothly rhymes everything he says.
Bull Horn: "So you the corn-fed fool with a alot of muscle mass, but now it's time for Bull Horn to get up in that ass!!"
by Gold_Shorts June 20, 2010
 
2.
Verb (to Bullhorn/Bullhorning) is the act of removing your significant others' nasal piercing during climax.
Lily: "Friend, I got my septum pierced!"

Friend: "Why?"

Lily: "Because Jay T wants to bullhorn me tonight!"

Friend: "That's some nasty shit."
by NLBA November 06, 2013
 
3.
Penis, Cock, Johnson, Weiner, Junk, love pole, etc.
I'm gonna give her the ol' bull horn!
by Klitman April 02, 2006
 
4.
Basically another word for bullshit. Can also be an amusing nickname for someone with long ratty hair.
Some Dude: "Hey i just ate a whole elephant tusk!"
Some Other Dude: "Thats a load of bullhorn."
by Fuck: Your name is shit. September 02, 2008