unsister 

The half sister of your half brother or half sister.

I got to see my unsister on Thanksgiving.

unsister by ridl February 26, 2009

Unsistering 

an action used when you unsister someone because your ‘sister’ forgets about you daily and stops posting about you not texting you.

Friend 1: Im going to unsister her

Friend 2: Omg no way you are insistering her

So you see unsistering is a word/ action used when a friend wants to be a dick and forget you

Unsistering by max luckwood August 23, 2018

Unsistering 

It’s an action you do when you ‘sister’ forgets about you and forgets about you in posts or tags and is being a dick. So you have to unsister her as a sister.

Friend1: I think I’m going to unsister her
Friend2: OMG NO WAY YOUR unsistering HER!

Unsistering by max luckwood August 23, 2018