- a female offspring having both parents in common with another offspring; female sibling.
- a female offspring having only one parent in common with another offspring.
- stepsister.
- a female friend or protector regarded as a sister.
- a thing regarded as feminine and associated as if by kinship with something else: The ships are sisters.
- a female fellow member, as of a church.
- a female member of a religious community that observes the simple vows of poverty, chastity, and obedience.
- a nurse in charge of a hospital ward; head nurse.
- a term used to refer to or address a fellow Black woman; soul sister.
- a woman who supports, promotes, or participates in feminism.
- a form of address used to a woman or girl, especially jocularly or contemptuously: Listen, sister, you've had enough.
- being or considered a sister; related by or as if by sisterhood: sister ships.
- having a close relationship with another because of shared interests, problems, or the like: We correspond with school children in our sister city.
- being one of an identical pair.
- a female person having the same parents as another person
- See half-sister, stepsister
- a female person who belongs to the same group, trade union, etc, as another or others
- a form of address to a woman or girl, used esp by Black people in the US
- a senior nurse
- a nun or a title given to a nun
- a woman fellow member of a Church or religious body
- belonging to the same class, fleet, etc, as another or others
- denoting any of the cells or cell components formed by division of a parent cell or cell component
