The term sister has many meanings. It can mean a metaphorical woman or a religious community. It can also mean something that is shared between a man and a woman. In some cases, the term can refer to the relationship between a man and his sister. Whether this relationship is biological or religious, it has a strong feminine character.
A female sibling is anyone who has the same parents as another individual. This may include a sister in a religious order, or a member of a sorority. A sister is also a member of another person’s family, as well as a sister-in-law. Another term for a sister is a sibling’s wife, known as a half sister or step sister. A brother is the male equivalent of a sister, while an aunt is the sister of a parent.
Sisters have many roles within the Catholic church. Many are religious, serving in hospitals or educating the poor. Some are cloistered and practice prayer. Other sisters are more active in the community and run classes and hospitals. Today, the word sistren is rarely used in the context of biological sisters in contemporary English, but it may be used in feminist or religious contexts and in poetic usage.
According to the American Heritage Dictionary, a sister is a female of the same sex. Sisters are close friends, share common ancestry, and are related by common purpose. A woman is also considered a sister if she is a member of a religious order. A nurse can be a sister if she is a senior nurse in a hospital.