Wifes sister, brothers sister.

also see SILF - Sister In Law I'd Fuck
"Man, Your SIL is Smokin hot"
by EVP January 22, 2008
An abbreviation for Strong Independent Lady.

a) Term used to protect a woman from being called a derogatory name.

b) Term used as code for a mean, mean, witchy, shrew of a woman
You: "Man, my boss is such a $%^&!"

Them: "No she is just a Strong and Independent Lady and you just can't handle that."

You: "Yes! thanks for High Roading me there. You're a SIL too!"

Them: "Thanks!"
by Grymm Deth September 30, 2009
My husband hadn't texted me back, so I just went to lunch alone with my SIL.
by shortysyndrome32 June 2, 2017
Adj; Bitch,Skank,Whore,Slut
by beetlebuggy April 7, 2021
1.Spouse I Love 2. Stud I Love to Fuck
silf or SILF can also be "Spouse I Love to Fuck" or "Stud I Love to Fuck".
1. My SIL and the MILF next door decided to have a girls night out.

2. My SIL was working last night when I hooked up with the SILF next door.
by Honeytaster December 9, 2007
something that is described as being cute, little, lovable, italian, gorgeous, and so on. Used when describing a person you feel affection towards.
Myles is such a sil! or Love you sil.
by lil em March 11, 2008
a shortened version of silly
gosh nyomi! you're such a sil!
by Caitlin C October 28, 2005