Big Montana is a derogatory term in regards to when a girl who is a whore
has so much vaginal penetration and wear n' tear, that she has vaginal folds that make her box
look like an Arby's Big Montana sandwich.
The abbreviation "BM" means the same thing, but is normally used in order to get some strange at the bar or get a drunk chick to show you her vagina
Example 1: "Fellas, that whore I hooked up with last night looked like she could have been a model for Arby's. All she had to do is spread her legs and show you her Big Montana and boom, she would have been the pinup for a #4 on the Arby's menu board."
Example 2: "Show me your fucking "BM" you cum drenched whore!"
1. A roast beef sandwich at Arby's.
2. A vagina that resembles a roast beef sandwich at Arby's. (In more than just looks...)
"Wow, that bitch sure does have a Big Montana between her legs."
when a females vagina has large, meaty flaps. usually in a roast beef kind of color. see "beef curtains", "t bone flaps." simular to a second rate fast food chain's large roast beef sandwhich.
"yo, i was with this girl last night.. she had a double serving of the big montana"
1. The largest of the Arby's Food chain Sandwiches.
2. A vagina that is loose and has been beat up like Grace Jones; lips are brown to brownish purple and resemble premium cuts of roast beef from a locally owned deli; sometime accompanied by Horsey Sauce.
That broad had a big montana, but I still ate it all.
A sloppy vagina, with meat curtains that run for miles. It hangs like sleeve of wizard and is so beat up that it looks like Roast Beef.
Her Vagina was nasty, that thing was a Big Montana. I'm tellin' you her Vagina was so loose, I could drive my truck through there.
The opposite of a sausage fest or testical festival. A party consisting of 90% or more females. A woman's vagina looks like a roast beef sandwich, hence a large gathering of vagina = the largest Arby's roast beef sandwich the BIG MONTANA.
Dude, you have got to get over to this party its a fucking big montana right now!
A donkey punch-tobogan, followed by a combination Cleveland steamer/Dutch oven.
"No way! An actual Big Montana?"
"You bet your ass dude! It was everything I've ever dreamed of!"