plural noun: sisters
a woman or girl in relation to other daughters and sons of her parents.
a close female friend or associate, especially a female fellow member of a labor union or other organization.
a member of a religious order or congregation of women.
a fellow woman seen in relation to feminist issues.
a black woman (chiefly used as a term of address by other black people).
a thing, especially an organization, that bears a relationship to another of common origin or allegiance or mutual association.