buttroar
Refers to a particularly violent eruption of gas from the anus after a singulary intense bong session. Rumor has that EZ E coinded the phrase while recording "Niggaz4Life" with NWA in 1991, but the term gained popularity in the california metalcore scene in the late 90's with bands like poison the well adamantium and downpour.
"mufafucka' let out a buttroar and spilled the bong."