Sister Flow 

Sister Flow- A softer way for a woman to refer to her period, monthly bleeding and/or menstrual cycle. In particular a word to use when her man wants some and the timing is not right so he cant have some.

Sorry baby not tonight; sister flow is home.

Sister Flow by Whit Whew May 9, 2009

Sister-in-law 

1)The princess-bitch your brother marries because he never asked for your advice.

"Hey, that girl sure acts like Paris Hilton but looks alot like Hillary Clinton."

"Yeah, that's my sister-in-law."

Sister-in-law by TheBetterKatie September 3, 2009

sister fucker

someone from Alabama

get off your your brother you sister fucker

sister fucker by tony's big bologna September 28, 2005

sister location 

a scary fnaf game

Sister Location is scary

sister location by SlyTy41704 June 11, 2017

Sister Project 

A sister project is a project related to another project by way of having the same parent organization.

Wiktionay is a sister project of Wikipedia which are both free-content projects by the non-profit Wikimedia Foundation.

Sister Project by wolfnine August 24, 2005

sister fucker

One who makes friends with a guy only to get close to his (usually younger) hot sister.

I thought Kevin was my friend... But it turned out he just wanted my sister. What a shameless sister fucker!

sister fucker by Urban_Fellow June 24, 2006

sister shot 

Golfing term. Means "it's up there, but you're not proud".

When one hits a total duffer, but it trickles along the ground and onto the green, one has hit a sister shot.

"Wow, that sister shot has set you up for par!"

sister shot by Jamie Douglas September 6, 2006