look up any word, like bukkake:
 
1.
(bris-tur)(n) 1) a female sibling that has more masculine qualities than feminine. 2) a male sibling that has more female qualities than male. 3) shim. (usually referred to as an it instead of a person)
This is my mom, dad, and the unfurtunate life form, my brister
by hozey777 August 10, 2005
 
2.
A combination of Brother and Sister, a hermaphrodite sibling.
"Is your new sibling going to be a new brother or sister?"
"It'll be a brister!"
by Lexibutt September 11, 2011
 
3.
if your brother has a sex change to a woman
he was a man but is living as a woman,and now she is my brister (brother-sister)
by worderamma 65 July 28, 2009