If something was completely unbelieveable/inconceivable, sometiems someone will exclaim "Sif!", a word used in internet circles.  This word could be used when describing the situation of when the exclamation occured.
by KinGAleX March 21, 2005
 Get the sifnessmug.
Get the sifnessmug. fo shizzle ma nizzle, sif i wouldn't!
by auTeX March 22, 2005
 Get the sifmug.
Get the sifmug. - "Whoah, did you see her knock out that 500-lb ex-convict/sexual predator?"
- "Yeah, she's a total SIF."
- "Yeah, she's a total SIF."
by ecjs March 10, 2009
 Get the SIFmug.
Get the SIFmug. by Raw Faith November 6, 2009
 Get the SIFmug.
Get the SIFmug. 'Smooshed In Face'
Someone who was either born with a 'Smooshed in Face', or had an accident with the baseball resulting in a 'Smooshed in Face'.
Someone who was either born with a 'Smooshed in Face', or had an accident with the baseball resulting in a 'Smooshed in Face'.
by Strings Jr. September 12, 2009
 Get the SIFmug.
Get the SIFmug. 
