See also: Sister



From Middle English sister, suster, from Old English swustor, sweoster, sweostor (sister, nun); from Proto-Germanic *swestēr (sister), from Proto-Indo-European *swésōr (sister). Cognate with Scots sister, syster (sister), West Frisian sus, suster (sister), Dutch zuster (sister), German Schwester (sister), Norwegian Bokmål søster (sister), Norwegian Nynorsk and Swedish syster (sister), Icelandic systir (sister), Gothic 𐍃𐍅𐌹𐍃𐍄𐌰𐍂 (swistar, sister), Latin soror (sister), Russian сестра́ (sestrá, sister), Lithuanian sesuo (sister), Albanian vajzë (girl, maiden), Sanskrit स्वसृ (svásṛ, sister), Persian خواهر(xâhar, sister).

In standard English, the form with i is due to contamination with Old Norse systir (sister).

The plural sistren is from Middle English sistren, a variant plural of sister, suster (sister); compare brethren.



sister (plural sisters or (archaic in most senses) sistren)

  1. A daughter of the same parents as another person; a female sibling.
    My sister is always driving me crazy.
  2. A female member of a religious order; especially one devoted to more active service; (informal) a nun.
    Michelle left behind her bank job and became a sister at the local convent.
  3. Any butterfly in the genus Adelpha, so named for the resemblance of the dark-colored wings to the black habit traditionally worn by nuns.
  4. (Britain) A senior or supervisory nurse, often in a hospital.
  5. Any woman or girl with whom a bond is felt through common membership of a race, profession, religion or organization, such as feminism.
    Connie was very close to her friend Judy and considered her to be her sister.
  6. (slang) A black woman.
  7. (informal) A form of address to a woman.
    What’s up, sister?
  8. A woman, in certain labour or socialist circles; also as a form of address.
    • Thank you, sister. I would like to thank the sister who just spoke.
  9. (attributively) An entity that has a special or affectionate, non-hierarchical relationship with another.
    sister publication, sister city, sister projects
  10. (computing theory) A node in a data structure that shares its parent with another node.
  11. (usually attributively) Something in the same class.
    sister ships, sister facility

Usage notesEdit

  • In Roman Catholicism, a distinction is often drawn (especially by members of female religious orders) between nuns and sisters, the former being cloistered and devoted primarily to prayer, the latter being more active, doing work such as operating hospitals, caring for the poor, or teaching.
  • The plural "sistren" is no longer commonly used for biological sisters in contemporary English (although it was in the past) but may be found in some religious, feminist, or poetic usage.




  • (daughter of common parents): sibling

Derived termsEdit

Related termsEdit


  • Gulf Arabic: سِسْتَر(sistər, female nurse)
  • Japanese: シスター (shisutā)
  • Korean: 시스터 (siseuteo)


The translations below need to be checked and inserted above into the appropriate translation tables, removing any numbers. Numbers do not necessarily match those in definitions. See instructions at Wiktionary:Entry layout#Translations.


sister (third-person singular simple present sisters, present participle sistering, simple past and past participle sistered)

  1. (transitive, construction) To strengthen (a supporting beam) by fastening a second beam alongside it.
    I’m trying to correct my sagging floor by sistering the joists.
  2. (obsolete, transitive) To be sister to; to resemble closely.
    • c. 1607, William Shakespeare, Pericles, Prince of Tyre, Act V, Scene 1
      Deep clerks she dumbs; and with her needle composes
      Nature's own shape, of bud, bird, branch, or berry,
      That even her art sisters the natural roses;
      Her inkle, silk, twin with the rubied cherry


Further readingEdit


Middle EnglishEdit



  1. Alternative form of suster



From Middle English sister, syster, forms of suster influenced by Old Norse systir, from Old English sweostor, swustor, sweoster, from Proto-Germanic *swestēr, from Proto-Indo-European *swésōr.



sister (plural sisteris)

  1. sister

Derived termsEdit