What is Facebook Blackout?
1.
when you go to check your facebook, get sucked in and realize an hour has passed and realize you just wasted so much time.
Rob: "I had the worst facebook blackout last night, I was supposed to be doing homework and I checked my facebook and I wasted an hour"
Kelly: "Sucks."
See
2.
A.) When, upon waking, one realizes that you went on Facebook last night blacked out - resulting in untold horrors.
B.) The actions of going on Facebook while in the middle of a alcohol-induced blackout.
A.) "Why did I send six vile Facebook messages last night to people I barely know? Oh, it must have been a Facebook Blackout..."
B) "Duuudeee...I am so going to send messages to this bitch!"
"Dude, don't do it, your in the middle of a Facebook blackout!"
See