n.
Pronunciation: ' sis-t ə r
Function: noun
Etymology: Middle English suster, sister, partly from Old English sweostor and partly from Old Norse systir sister; akin to Latin soror sister, Sanskrit svas ṛ
Date: before 12th century
1 : a female who has one or both parents in common with another
2 often capitalized a : a member of a women's religious order (as of nuns or deaconesses) especially : one of a Roman Catholic congregation under simple vows b : a girl or woman who is a member of a Christian church
3 a : a girl or woman regarded as a comrade b : a girl or woman who shares with another a common national or racial origin especially : a black girl or woman
4 : one that is closely similar to or associated with another < sister schools> < sister cities>
5 chiefly British : NURSE
6 a : GIRL , WOMAN b : PERSON ― usually used in the phrase weak sister
7 : a member of a sorority