fast girl 

can be either someone whos a slut( or at least gives the idea that she's easy) and/or a really fast runner
( usually the best is a combination of both, but being more of a flirt than actually putting out)

"fast girls finish first" -nike running shirt

fast girl by xcrunner06 May 15, 2006

fast girl 

A girl who is knida whore-like and easy to get in the sack.

"Man, that Ashley really is a fast girl" "Yeah man, I fucked that bitch up the wall the day I met Her!"

fast girl by ATown BTown April 27, 2006

Fast Girl 

A girl who has little ambition in life. One who parties heavily and lacks purpose, job or career goals.

I want to hit it with that fast girl.

No one wants to date a fast girl.

Fast Girl by MissVirginific September 7, 2010

Girl-fast 

When a guy abstains from all female company and communication for an extended period of time (usually 30 days).

Sergiu: Hey Joe? you still chatting to Erika?
Joe: Naw man, I've had my fill. I'm on a girl-fast.

Girl-fast by Jimmy Struthers January 10, 2012

Fast ass lil girl

11-16 year old little girls being sexual or flirting with boys/girls. Acting grown around boys, BASICALLY BEING A HOE AT A YOUNG AGE.

Mom: *On Phone* Yeah Girl I caught ShuhNeyNey flirting with some boys in the parking lot wearing me hoop earrings and some tight ass shorts. I believe im raising a fast ass lil girl. I whooped her ass tho, Hopefully she will change before she end up pregnant at 16.

Fast ass lil girl by ISwearImaBeatHerUp May 28, 2019

Fastgirl 

A woman who rides her R1.

A woman who is capable of introducing you to a whole world of hurt if you disprespect her.

Daaamn you see that Fastgirl? She rides the shit out of her R1!

Fastgirl by Fastgirl March 9, 2009