A penitentiary is a prison, especially a large one run by a state or by the country, and the word shows up most often in official names: the state penitentiary, the federal penitentiary. In ordinary talk, American speakers still say prison far more; penitentiary sounds formal, legal, and a little old-fashioned, the kind of word you read on a sign or in a news report rather than say over dinner. British English almost never uses it for a local jail; prison is the everyday word there too.

A penitentiarypenitentiary is a prison是監獄，especially a large one run by a state or by the country尤其是州政府或國家經營的大型監獄，and the word shows up most often in official names這個字最常出現在正式名稱裡：the state penitentiary, the federal penitentiary像the state penitentiary（州立監獄）、the federal penitentiary（聯邦監獄）。In ordinary talk平常講話，American speakers still say prison far more美國人還是比較常說prison；penitentiary sounds formal, legal, and a little old-fashionedpenitentiary聽起來正式、法律味重，還有點老派，the kind of word you read on a sign or in a news report是那種你會在告示牌或新聞報導上看到，rather than say over dinner而不是吃飯時會說出口的字。British English almost never uses it for a local jail英式英文幾乎不會用它來指當地的一間監獄；prison is the everyday word there too在那裡prison也是日常用的字。

The name is more hopeful than the place usually is. It comes from penitence — feeling sorry — because in the 1790s Quakers in Pennsylvania wanted a prison where people would sit with what they had done and try to change, not only be locked away. That idea did not last in any simple way, but the name did.

The name is more hopeful than the place usually is這個名字比這個地方通常給人的感覺更有希望。It comes from penitence — feeling sorry它來自penitence，也就是感到懊悔——because in the 1790s Quakers in Pennsylvania wanted a prison因為在1790年代，賓州的貴格會教徒想要一種監獄，where people would sit with what they had done and try to change讓犯人能靜下來面對自己做過的事、試著改變，not only be locked away而不只是被關起來。That idea did not last in any simple way那個理想並沒有簡單地延續下來，but the name did但這個名字留了下來。

You may also meet it as an adjective in very formal writing (a penitentiary sentence), still pointing at prison, not at the feeling of being sorry.

You may also meet it as an adjective in very formal writing在非常正式的文章裡，你也可能碰到它當形容詞用（a penitentiary sentence像a penitentiary sentence），still pointing at prison, not at the feeling of being sorry指的還是監獄，不是懊悔的那種感覺。