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Facebook, the most addictive website in the world. Also 'crackbook.' In some circumstances, smackbook may be more appropriate to say than crackbook.
Yesterday I spent 14 hours on smackbook, which now rivals only my heroine addiction in competition for my free time.

"Hey man, I saw your girlfriend dumped you on crackbook! You are one pathetic loser!"
"Seriously, I am so done with this smackbook."
by The Anarchist in the Library April 29, 2009
1. A guestbook signed generally by the insane
2. a guestbook which is used as a forum
Sign the smack book you slag
by Jesus January 08, 2004