A silf is a "sister i'd like to fuck". it is the same idea as a milf. Silfs are usually absolutely georgous, sexy, irresistable, and extremely flirty
Guy 1: "Dude you have to meet my sister Alie, she's a total silf"
by alwaysaladybug February 02, 2011
Sheep I'd Like to Fuck.

Jon: Hey Danny K.
Danny: Whats up Jon?
Jon: That sheep over there is one sexy Silf.
Danny: You feeling a double team?
Jon: I'm feeling a double team.
by Edaan Brook October 26, 2007
A person's sister you will like to fuck
I told my friend he had a silf
by ApocalypticaX November 01, 2009
Shrimp I'd Like To Fuck
Hey Jim, check out the whiskers on that small pink slightly curved sea dweller! A regular SILF and no mistake! High five!
by Roger McTodger November 16, 2004
acronym for sister i'd like to fuck. derived from milf another acronym this time for mother id like to fuck.
damn phil's sister is a fucking silf
by Allay June 17, 2004
Slut I Like to Fuck
She looks awesome. She's SILF definately!
by Cuntslapdiver June 30, 2010
Sheep I'd Like to Fuck sheep shagger} - A common welshism/bristolian term, often quoted whilst at the local farmers market.
'Cooor, that there Black Mountains a bee-uty!'

'Aye, she's a right S.I.L.F'
by PoL, Gas, Cymraeg. July 03, 2008

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from daily@urbandictionary.com. We'll never spam you.