1. the sexual act of following anal sex immediately with oral sex, which causes residual fecal matter to coagulate on the recipient's upper lip, resembling a Mexican handlebar moustache
2. Unexplained sexual position taught by South Park character Mr. Garrison to his kindergarten class.
(1) 'Naw, I gave that slut Jessica a Filthy Sanchez, dude, not the other way around!'
(2) 'Ike, do you know what a "Filthy Sanchez" is?'
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.