Siul

A man who either consciously or unconsciously is attracted to and/or wants to have a sexual relationship with his sister.
"Man that girl is hot. She looks just like my sister."

"Dude, why do you bring up your sister in every conversation? ESPECIALLY when it's involving a hot chick? You're a Siul. That's so gross."
by __zsasz__ March 27, 2009
mugGet the Siul mug.