Definitions by fagbag v2

bsitwuab 

Best Sister In The Whole Universe and Beyond
-ITWUAB: greatest and sweetest extension.

can also be used in other words.

SUCH AS:
bsitwww, (best sister in the whole wide world) or bbfitwuab, (best boyfriend in the whole universe and beyond)

"She's definitely my bsitwuab!"

"Wtf? What's that?"

"It means best sister in the whole universe and beyond. You're just jealous" <3

bsitwuab by fagbag v2 June 30, 2010