像姊妹一樣的關係
這一家就是核心本身：先有家裡的姊妹關係，再把那份親近借給沒有血緣的人。
noun · C1
The fact of being sisters, or the relationship between two or more women or girls in the same family.
姊妹關係
核心畫面
One way to hold this word: the ending -hood turns a person into a state, so sisterhood can be pictured as being sisters. Start with two girls in one family and the closeness between them. Then let that same closeness stretch over women who are not related at all but stand together for the same thing. Then let it stretch once more, to a house of women who choose to live as sisters every day. The family tie is the picture; the other uses borrow it.
可以想成：字尾 -hood 把一個身分變成一種狀態，所以 sisterhood 的畫面就是「當姊妹」這件事。先看家裡…更多收起
可以想成：字尾 -hood 把一個身分變成一種狀態，所以 sisterhood 的畫面就是「當姊妹」這件事。先看家裡真的有血緣的兩姊妹，那份親近是原型。接著把同樣的親近借出去，蓋在沒有血緣、卻站在一起的女性身上。再借一次，就變成一整屋子自願以姊妹相處、一起過宗教生活的女性。這個字從頭到尾都在講同一種關係，只是套在不同的人身上。From the word’s history
Wiktionary records sisterhood as Middle English susterhede, that is sister plus -hood, with the ending later respelled. The ending is what does the work: it names the state of being the thing, which is exactly the picture the modern senses share.
字典記載 sisterhood 來自中古英語 susterhede，也就是 sister 加上 -hood，只是字尾後來換了寫法。關鍵在字尾：-hood 把「姊妹」變成「當姊妹的狀態」，這正好就是這個字今天各個用法共用的畫面。
Wiktionary entry for sisterhood, supplied in this batch's evidence packet: From Middle English susterhede; equivalent to sister + -hood (with a modification in the suffix).
Two branches
以姊妹相處的團體
同樣是「以姊妹相處」，但這裡指的不是感覺，而是一群真的住在一起的人，所以可以數、可以加入。
noun · B2
A group of women who live together as a religious community, following the same rules and sharing the same daily religious life.
女修會