A euphemism, or replacement word, for those who are too pussy to use the actual swearword which is bullshit. The word has now evolved to include broader meanings that include dissing someone or simply emphasizing a statement.
Danny: Bra, u've just been fired!
Alvy: That's bulldust!
Alvy: What the hell is that bulldust u're wearing on your feet??
Danny: I got me some, i got me some, i got me some Bathing Apes!
Alvy: That's bulldust!
Alvy: What the hell is that bulldust u're wearing on your feet??
Danny: I got me some, i got me some, i got me some Bathing Apes!
by Danny2sexy April 4, 2008