Oversized, over-used, stretched out vagina lips, hanging from the crotch area, resting on the inner thigh, as if to be an open faced roast beef sandwich.
When your at a party, you meet a chick, you stick your hands down her pants, and there's more meat in your hands than in hers. That's open faced roast beef.
by BT Cruiser November 17, 2007
Get the open faced roast beefmug. by Emma Putnam January 16, 2008
Get the roast beef curtains with mayomug. 
Damn bitch u some fine R.B.S. (Roast Beef Syndrome)
Ewww I can smell that R.B.S. outside of your pants
Put that R.B.S right here.
Ewww I can smell that R.B.S. outside of your pants
Put that R.B.S right here.
by GuCcI May 27, 2013
Get the R.B.S. (Roast Beef Syndrome)mug. When a botha pulls huge pussy lips over a bitch's head and beats his cock violently off her forehead.
by Tim S. Trickler February 6, 2009
Get the Roast Beef Slapdownmug. by Bubba November 21, 2003
Get the spit roasted ass homug. The girls Roast beef au jus was so foul it looked like it could be put in a roll with some gravy, horseradish and a slice of provalone cheese.
by Murph McGirt December 9, 2003
Get the Roast beef Au Jusmug.