A bet that pays off big or just something that is awesome. Comes from the racetrack, where a winning bet on a big ticket pays so many zeros that it looks like the dots on double sixes ("boxcars" in dice). Can be used in combination with ship it.
Man, I hit that moneyline parlay and it paid boxcars.

Dude, did you see that girl's ass? It was boxcars.

Guy 1: We just scored an 8th and it's nuggy.
Guy 2: Boxcars.

Guy 1: That slampig wants to f you later
Guy 2: Boxcars, ship it.
by smart money February 13, 2006
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An adjective describing someone that is anti-semetic
Dude, he's so Boxcar he makes Hitler look like Sammy Davis Jr.
by Revdrgiggles January 15, 2007
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Crazily stupid or idiotic, insane. Used to describe a person entirely lacking in common sense.

crazy, stupid, retarded, insane, half-baked, witless, a few crayons short of a full 52
That guy is boxcars, he just dropped his ipod in the toilet.
by Van's Little Wing April 27, 2011
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An extra pocket sewn into the inside of men's underwear so that older men can have their scrotum supported.
Grandpa was hanging so low he needed a boxcar so he could wear his shorts.
by TruckdrivingMonkey June 29, 2014
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One of those disgusting looking rectangular vehicles like the Scion xB. Most people would never buy such an ugly thing, but some just have strange tastes and preferences
The Laguna Beach youth parked his new Scion xB boxcar in the cul de sac, where it became an eyesore to the neighbors
by Boxcar Bob October 25, 2006
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1. A party or social gathering often taking place inside an abandoned or otherwise derelict boxcar.

2. A party hastily thrown together by hooligans, usually involving depravity and debauchery.

3. A party or social gathering where everyone dresses up as newsies and flappers.

4. A race with contestants dressed up as newsies racing vintage pedal cars.
Mr Kemp invited me and Atticus to a boxcar social tomorrow evening.

Some old friends are holding a boxcar social but I don’t know if I will go, the cops usually show up and ruin the fun.

A boxcar social is being held a few blocks away. Would you like to dress up and head on over?
by gypsywrangler January 3, 2022
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the act of having sex with another persons colostomy hole.
there was this old man who had surgery so that he had to use a colostomy hole in order to poop, and he would go down to the jail yard and sell his colostomy hole for 5 dollars to the inmates so that they could fuck it. the man is from Philadelphia and his colostomy hole is packed like a boxcar so that is why its called a Philadelphia boxcar.
by supon and keenchode April 19, 2013
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