便所

Wasei kango (和(わ)製(せい)漢(かん)語(ご)), orthographically borrowed from Japanese 便(べん)所(じょ) (benjo).^[1]

便所

1. (chiefly Northeastern Mandarin, Taiwanese Hokkien, Taiwanese Hakka) bathroom; restroom; lavatory; toilet

   便所佇佗位？ [Taiwanese Hokkien, trad.]
   便所伫佗位？ [Taiwanese Hokkien, simp.]

   Piān-só͘ tī tó-ūi? [Pe̍h-ōe-jī]

   Where's the toilet?

   • 2021, 林榮澤, 法雨甘霖：白水聖帝法語輯, 一貫道學研究院文獻館, →DOI, →ISBN, page 286:

     你看我九十三歲了，我坐這兒跟坐飛機一樣，我坐飛機去美國，十二個小時，起來一次上便所，我現在還可以八個小時不上便所，六個小時不喝水，這是普普通通，我現在還可以，這才知道早已明白一點意思。 [MSC, trad.]
     你看我九十三岁了，我坐这儿跟坐飞机一样，我坐飞机去美国，十二个小时，起来一次上便所，我现在还可以八个小时不上便所，六个小时不喝水，这是普普通通，我现在还可以，这才知道早已明白一点意思。 [MSC, simp.]

     Nǐ kàn wǒ jiǔshísān suì le, wǒ zuò zhèr gēn zuò fēijī yīyàng, wǒ zuò fēijī qù Měiguó, shí'èr ge xiǎoshí, qǐlái yīcì shàng biànsuǒ, wǒ xiànzài hái kěyǐ bā ge xiǎoshí bù shàng biànsuǒ, liù ge xiǎoshí bù hēshuǐ, zhè shì pǔpǔtōngtōng, wǒ xiànzài hái kěyǐ, zhè cái zhīdào zǎoyǐ míngbai yīdiǎn yìsī. [Pinyin]

     See, I am 93 years old. When I sit here, it is like going on a plane. When I take the plane to the United States, for the 12 hours, I get up to go to the bathroom once. Now, I can still go for eight hours without going to the bathroom and six hours without drinking water. This is quite ordinary. I still can; then I realized that I had long understood some of it.

Appears to be a coinage in Japanese^[1] from Middle Chinese-derived roots, as a compound of 便 (ben, “convenience, ease”, also meaning “bodily waste; bowel movement”) +‎ 所 (sho, “place”). The sho changes to jo as an instance of rendaku (連(れん)濁(だく)). Compare English expressions seat of ease, house of ease, also pooper, shitter.

First cited in works from the late 1400s.^[1]

• (Tokyo) べんじょ [bèńjóꜜ] (Odaka – [3])^[2]
• IPA^(key): [bẽ̞ɲ̟d͡ʑo̞]

便(べん)所(じょ) • (benjo) 

1. [from late 1400s] (dated) bathroom, restroom, lavatory, toilet
2. (gambling slang) a pachinko machine one can use leftover balls on.

While up until the 1970s, this term or the honorific お便所(べんじょ) (o-benjo) was the preferred polite term to refer to a bathroom, it has now been largely replaced with お手洗(てあら)い (o-tearai, “washroom”)—or even トイレ (toire, “toilet”)—and sounds dated, and even seen as vulgar.

• トイレ (toire), おトイレ (o-toire)
• 手洗(てあら)い (tearai), お手洗(てあら)い (otearai, “washroom”)
• 化粧室 (keshōshitsu, “lavatory”, literally “make-up room, powder room”) – used in public spaces, like shops or airplane, more as the written sign than in speech.

• お便所(べんじょ) (o-benjo)

便所 • (byeonso) (hangeul 변소)

1. hanja form^? of 변소 (“bathroom, restroom, lavatory, toilet”)