0 a girl or woman who has the same parents as another person: --
[ as form of address ] Excuse me, Sister, could I have some water?
[ as form of address ] God bless you, Sister.
Sister Bernadette
[ as form of address ] OK, sister, move it!
[ as form of address ] "We must continue the fight, sisters!"
Lynn's such a good friend - she's like a sister to me.
Sophie and Emily are sisters.
1 belonging to a pair or group of similar and related things, such as businesses, usually owned or operated by the same person or organization: --
the US battleship Missouri and her sister ship, the Wisconsin
3 used to describe one of the organizations or companies in a pair or group of similar organizations when referring to it in relation to the others: --
sister company/organization
The competition is being run in conjunction with our sister publication Money Observer.
I've got a family crisis on my hands - my 16-year-old sister is pregnant.
Not content with having upset my parents, he then insulted my sister!
I do like her - after all, she is my sister.
You're confusing me with my sister, - she's the one studying drama.
While I struggled, my sister coasted through school with top grades.