Foster

To sign off randomly on people after they IM you.
To be bad at IM
(verb)

Dude this girl fostered me on IM today it so wasnt chilll man i didnt even mean to say hi to her....

by Luke Foster Frodo October 27, 2010

foster

A incredibly hot, damn fine piece of ass.

"man that leya is a total foster!"

"did you see that foster, Id love to hit that."

by L.E April 09, 2007

Foster's

Short for Foster's Home for Imaginary friends. When kids get too old they don't need imaginary friends anymore so they stay at Foster's until they get adopted by another child (presumably with no imagination of their own).
Foster herself is a little old lady who still has her imaginary bunny friend.

Mr. Unicorn, we regret to inform you little Stacy is dead, so you'll be staying at Foster's from now on.

by unicorny July 31, 2006

fostered

When a girl pukes while sucking a guys dick.

That girl totally just fostered that guy.

by theman17 November 09, 2010

foster

In regard to video games, to shoot an opposing player in either the crotch or ass. Also referred to as "Buttering" as in the episode of South Park where Butters shoots everyone in the crotch.

Guy 1: "Dude, you totally just shot him in the dick!"

Guy 2: "FOSTERED!"

by Arkem3 June 25, 2011

foster

a word for someone who has more then one STD.

I know i have a foster on my cock after hooking up with that slam pig the other night.

by Barry Gorman October 12, 2006

foster

to step on, usu. in a fight

That guy just fostered the other guy in the nuts.

by Excello April 13, 2008