1 definition by Brainrotgobrrrr

"SILF" is an acronym for "Sister I'd Love to Fuck", which means someone's sister who'd you like to have sex with.
Boy #1: Gosh- Lily's sister is such a silf!
Boy #2: They are both silfs dude!
Girl #1: You guys are both right! They are silfs.
by Brainrotgobrrrr April 26, 2021
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