Main Entry: sis·ter

Pronunciation: \ˈsis-tər\

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 svasṛ

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