Fb is short for many things I'm sure, but what it is most commonly known and used for is FaceBook.

Facebook is a homepage where one can share photos, status updates about their life etc.

Fb is not something one says while speaking, it is an internet chat or sms abbreviation.
"Omg, he totally wrote to me on Fb!"

"I uploaded all the photos from last night on Fb!"
by Mrs.Potatohead October 06, 2012
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fb stands for free base meaning they have a to themselves i.e. parents aren't home
Yeo it's a fb tonight u tryna come over?
by torontpgyalnem June 18, 2019
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"Come on man, you've been hittin' up that FB status all day."
by Mos before Bros April 16, 2007
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A troll who likes to stir up trouble on the fark.com messageboards.
I think we've got ourselves another fb- on our hands.
by Farker August 02, 2003
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gods most beautiful creation-the perfect combination
bronwyn: is that..
emily: ...yes it is
bronwyn: i want to touch it
emily: NOO! do not touch my precious
bronwyn: but i need it all over me
emily: no, fb/a is mine, all mine
by brownynandemilylovesfb/a March 06, 2008
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