18th base

growing a penis or vagina and having sex with yourself

"woh dude I went to 18th base last night"
"..."

based balls

Based balls were basically the first name for crack during it's intial years, circa 85-88. Crack first appeared on the streets of NYC in about 1985, although freebase was smoked prior to that, the addition of baking soda created a whole new monster. Based balls was what the "Wild Cowboys" gang called their first batch of potent crack to hit the street in large numbers.
The Wild Cowboys were a notorious gang based mainly in Washington Heights, Manhattan and parts of the South Bronx. Based balls were sold at many spots throughout both The Heights and in the Bronx. they usually came in large, cooked up rocks in vials sold for $20 and up. The reason they choose the name was because they resembled tinier sized baseballs
Crack known as "Based Balls" was strictly a New York Ccity term, known mostly in Washington Heights. Although crack spread to all of the boroughs, and nationwide, based balls was a name used solely by the infamous Cowboys to solidify their reign as crack kings of the 80's and early 90's.

Based Balls were first sold at 174th and Audubon where the Wild cowboys ruled the streets.

49th base

For male: Sticking your penis in the exhaust pipe of a f1 car

For Female: Sticking a f1 car exhaust pipe into your vagina

Man I went to the 49th base last night!

Fuck, thats like better then sex!

76th Base

Oddly enough, 76th base is nothing more then a candle lit dinner in a cliched romantic destination. I know, what a let down.

Man 1: Dude, I heard you took your girlfriend to Paris.
Man 2: Yeah, we got to 76th base at an Italian restaurant by the Eiffel Tower.
Man 1: Oh well that's sweet... you fuck her after?
Man 2: No.
Man 1: Puss

19th base

having sex with an inanimate object yet still reaching an orgasm. the object must also orgasm.

only 2 people are known to have achieved this. ron jeremy and chuck norris

ron jeremy: i got to 19th base with that sexy tree down the road

chuck norris: *ROUNDHOUSE KICK*

fourth base

The final stage in a relationship that involves sexual intercourse.

First Base -- Making Out (tongue included)
Second Base -- Rubbing, Dry Humping, grinding.
Third Base -- Oral Sex
Fourth Base -- Sex

"I can't believe it, he got to fourth base on his first date with her!"

50th base

to go to 4th base with a different woman (or man) in all 50 states.

You:50! I finally did 50th base!

Partner: I thought this was fourth base!

You: it is for you, but not for me!