sister

/ˈsɪstər/
noun
  1. A female sibling; a girl or woman who has the same parents as another person.
    • My sister and I share a bedroom.
    • I called my sister to tell her the good news.
    • She is the oldest sister in a family of four children.
  2. A woman who is a member of the same group, organization, or movement as others, often used to express solidarity.
    • The women in the club call each other sister.
    • We are all sisters in this community.
    • She is a sister in the fight for equal rights.
  3. A nun; a woman who belongs to a religious order.
    • The sisters at the convent pray every morning.
    • She decided to become a sister and dedicate her life to service.
    • Sister Mary teaches at the local school.
  4. A female friend or close companion, especially one considered like a sibling.
    • We've been sisters since kindergarten.
    • He introduced his best friend as his sister from another mother.
    • She's not just a friend; she's my sister.
Synonyms
Antonyms
adjective
  1. Belonging to the same group, type, or organization; closely related or similar.
    • The company has a sister store in the next town.
    • Our sister school in France exchanges students with us.
    • The two cities are sister cities with a long history of cooperation.