Definition of "sister"
sister
/ˈsɪs.tə(ɹ)/
noun
plural sisters or (archaic in most senses) sistren
(attributively) An entity that has a special or affectionate, non-hierarchical relationship with another.
plural sisters or (archaic in most senses) sistren
(attributively) An entity that has a special or affectionate, non-hierarchical relationship with another.