Nineteenth base is when you bite someone's balls off and stick it up your butt at exactly 10:17 am in a physics lecture at the front of the classroom while simultaneously touching the TA's areolae and solving a very very hard physics problem involving heat transfer of energy, kinematics and forces. All while drinking a extra large coffee - double double from mcdonalds that you got for free because you stole it because you're a naughty boy.
by naaaaaaaaaaaaaaaaan November 09, 2017

by Monday-Friday September 15, 2020

A term that can only be used in the same sentence as the most digusting of sluts. She is a literal cum dumpster if she can get past filthy fifths...
Just think about the term for a moment...Nasty nineteenths. Thats fucking gross. Even sloppy seconds is pretty groady.
Just think about the term for a moment...Nasty nineteenths. Thats fucking gross. Even sloppy seconds is pretty groady.
Mike: So...you bang Jenny last week?
Devon: I was her filthy fifth. What were you?
Mike: Her nasty nineteenth!
Devon: ...that's not something to be proud of.
Mike: I know. I've got herpes, gonorrhea, crabs...
Devon: Oh...sorry dude.
Mike: Hmm? It's not your fault.
Devon: She was clean before I got her...
Mike: Nasty Nineteenths are gross now...
Devon: THEY WERE GROSS BEFORE!
Devon: I was her filthy fifth. What were you?
Mike: Her nasty nineteenth!
Devon: ...that's not something to be proud of.
Mike: I know. I've got herpes, gonorrhea, crabs...
Devon: Oh...sorry dude.
Mike: Hmm? It's not your fault.
Devon: She was clean before I got her...
Mike: Nasty Nineteenths are gross now...
Devon: THEY WERE GROSS BEFORE!
by MoRPHiNe April 14, 2008

by Chris Adamo April 20, 2007

It is used to compliment a person(potentially your love interest).To call someone this means they have got your undivided attention/they are the only thing you see/they are just beautiful/you feel at peace when you're with them.
by Undsay January 24, 2023
