#sister.member  a female person who is a fellow member of a sorority or labor union or other group; "none of her sisters would betray her"
  supertype:  member  one of the persons who compose a social group (especially individuals who have joined and participates in a group organization); "only members will be admitted"; "a member of the faculty"; "she was introduced to all the members of his family"
  member of:  sorority
  subtype:  Beguine  (Roman Catholic) a member of a lay sisterhood (one of several founded in the Netherlands in the 12th and 13th centuries); though not taking religious vows the sisters followed an austere life

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