SIF

Acronym for sister i'd fuck.

hey, what's up sif?

by Chyo Mamma April 9, 2009

SIF

'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'.

A) "Dude, that girl is pretty cute."
B) "What? are you kidding she's a total SIF."

by Strings Jr. September 12, 2009

SIF

SIF means "Seat In Front."
It's a term used by unicycle riders to describe a way of doing a trick with the seat in front of you rather then the seat under your butt.

Example: "If you do the hop SIF, you can get more height."

by Ivan J July 23, 2008

SIF

a short term for silly ignorant fag

jamie: yo adam that ambers being a ryt SIF
adam: ye man i agree what a SIF

by jamie the Great May 25, 2007

Sif

that big ass wolf from dark souls that has a sword

Sif is such a tearjerking boss if you think about it.

by smol_child June 12, 2018

sifs

Secret
Internet
Fatty

guy 1 >hey did you talk to tori today?
guy 2> no i found out she and her friends are SIFS

by jenFACE April 14, 2006

sif

1. Secret Internet Fatty; 2. Any person who takes flattering photos of themselves to hide their bulging fat rolls and dosn't put up a disclamer to those who seem to be ... interested.

"So I met this girl on myspace right. We talked for weeks and figured it was time to hang out and get a cup of coffee. Oh man, I walked in and took one look at her ... yelled SIF and then promptly left. It was horrid"

by detroitgoth December 9, 2006