sister

1. (British) A senior or supervisory nurse, often in a hospital.Synonyms: charge nurseBritish

2. (African-American Vernacular, slang, sometimes capitalized) A black woman.Examples: "A fly sister rolled in with a suitcase full of hip-hop novels called The Glamorous Life, and an African brother with long dreads wanted to sell them some incense and some fake Jacob watches."; "The short “naps” of the average Sister do not sway in the wind as that of a blonde."; "And now, social media has made it worse. From Facebook to Twitter, I get all kinds of invitations. Recently a sister inboxed me on Facebook and told me that she knew for a fact that I wanted her and she wanted me."capitalizedslangsometimes

3. (informal) A form of address to a woman.Examples: "What’s up, sister?"; ""Listen, sister. I've got a job for you.""Synonyms: darling, dear, love, lady, miss, petinformal

4. (attributively) An entity that has a special or affectionate, non-hierarchical relationship with another.Examples: "sister publication"; "sister city"; "sister projects"Synonyms: affiliate, affiliatedattributive

5. (computing theory) A node in a data structure that shares its parent with another node.

6. (usually attributively) Something in the same class.Examples: "sister ships"; "sister facility"; "Within the ABCZ clade, Arecanae are sister of a group that includes all of the other taxa, and the latter fall into two major clades."attributiveusually