sister sister /ˈsɪstɝ/

noun

1. () A female person who has the same parents as another person  ( sis [Informal] , sister )
   a female person who has the same parents as another person
    My sister married a musician
   my sister married a musician
   
   
2. A female person who is a fellow member of a sorority or labor union or other group  ( sister )
   a female person who is a fellow member of a sorority or labor union or other group
    None of her sisters would betray her
   none of her sisters would betray her
   

 Sister

1. (Roman Catholic Church) a title given to a nun (and used as a form of address)  ( Sister )
   (Roman Catholic Church) a title given to a nun (and used as a form of address)
    The Sisters taught her to love God
   the Sisters taught her to love God