在

在 (Kangxi radical 32, 土+3, 6 strokes, cangjie input 大中土 (KLG), four-corner 4021₄, composition ⿸𠂇⿰丨土)

• 恠, 茬, 𠈚, 𠡘, 𠱽, 𭓁, 𭖘, 𣑊, 𥒒, 𫞼, 𨀬, 𩶦, 𡖪, 𭻟, 𮔒, 𭆩, 𣄒, 𢙮, 𥩴
• 𰌻, 𰛢

• Kangxi Dictionary: not present, would follow page 224, character 18
• Dai Kanwa Jiten: character 4881
• Dae Jaweon: page 455, character 14
• Hanyu Da Zidian (first edition): volume 1, page 418, character 7
• Unihan data for U+5728

• 在 on Wikidata.Wikidata

Historical forms of the character 在
Shang	Western Zhou	Spring and Autumn	Warring States	Shuowen Jiezi (compiled in Han)	Liushutong (compiled in Ming)	Libian (compiled in Qing)
Oracle bone script	Bronze inscriptions	Bronze inscriptions	Qin slip script	Small seal script	Transcribed ancient scripts	Clerical script

Phonetic compound (OC *zlɯːʔ, *zlɯːs): phonetic 才 (OC *zlɯː, *zlɯːs) + phonetic 士 (OC *zrɯʔ).

Now phono-semantic compound (形聲／形声, OC *zlɯːʔ, *zlɯːs) : phonetic 才 (OC *zlɯː, *zlɯːs) + semantic 土 (“earth”).

在 was often visually identical to 才 (OC *zlɯː, *zlɯːs, “sprout”) in the oracle bone script and some of the bronze inscriptions. It may be either a phonetic loan or a figurative derivative.

Probably related to 栽 (OC *ʔslɯː, “to plant”) (Schuessler, 2007).

This etymology is incomplete. You can help Wiktionary by elaborating on the origins of this term.

在

1. to exist; to be alive

   在嗎？／在吗？  ―  Zài ma?  ―  Are you here?

   • c. 475 - 221 BCE, Disciples of Confucius, “學而 [Xue Er]”, in James Legge, transl., 論語 [The Analects of Confucius]:

     父在，觀其志；父沒，觀其行。 [Classical Chinese, trad.]
     父在，观其志；父没，观其行。 [Classical Chinese, simp.]

     Fù zài, guān qí zhì; fù mò, guān qí xíng. [Pinyin]

     While a man's father is alive, look at the bent of his will; when his father is dead, look at his conduct.

2. to be at; to be in; to be located

   他在哪裡？／他在哪里？  ―  Tā zài nǎlǐ?  ―  Where is he?

   旅館在新購物中心附近。 [MSC, trad.]
   旅馆在新购物中心附近。 [MSC, simp.]

   Lǚguǎn zài xīn gòuwù zhōngxīn fùjìn. [Pinyin]

   The hotel is located near the new shopping center.

   我在只塊。／我在只块。 [Teochew]  ―  ua² do⁶ zi² go³. [Peng'im]  ―  I am here.

3. be ...-ing; in the middle of doing something (indicating an action in progress)

   我在看電視。／我在看电视。  ―  Wǒ zài kàn diànshì.  ―  I'm watching TV.

   他在吃米飯。／他在吃米饭。  ―  Tā zài chī mǐfàn.  ―  He's eating rice.

   我在食飯。／我在食饭。 [Teochew]  ―  ua² do⁶ ziah⁸ beng⁷. [Peng'im]  ―  I am eating.

4. (located) in; at

   我住在中國。／我住在中国。  ―  Wǒ zhù zài Zhōngguó.  ―  I live in China.

   我們在當地報紙上登了一則廣告。 [MSC, trad.]
   我们在当地报纸上登了一则广告。 [MSC, simp.]

   Wǒmen zài dāngdì bàozhǐ shàng dēng le yī zé guǎnggào. [Pinyin]

   We put an ad in the local paper.

   每天下午他在家裡工作。 [MSC, trad.]
   每天下午他在家里工作。 [MSC, simp.]

   Měitiān xiàwǔ tā zài jiālǐ gōngzuò. [Pinyin]

   Every afternoon he works at home.

5. during; in

   你打算在假期裡做什麼？ [MSC, trad.]
   你打算在假期里做什么？ [MSC, simp.]

   Nǐ dǎsuàn zài jiàqī lǐ zuò shénme? [Pinyin]

   What do you plan to do during the holidays?

   他的日記在他生前未曾發表過。 [MSC, trad.]
   他的日记在他生前未曾发表过。 [MSC, simp.]

   Tā de rìjì zài tā shēngqián wèicéng fābiǎo guò. [Pinyin]

   His diary was not published during his lifetime.

6. to lie in; to rest with

   事在人為／事在人为  ―  shìzàirénwéi  ―  human effort can achieve everything;

   成功貴在堅持。／成功贵在坚持。  ―  Chénggōng guì zài jiānchí.  ―  Perseverance is vital to success.

   去不去在你自己。 [MSC, trad. and simp.]

   Qù bù qù zài nǐ zìjǐ. [Pinyin]

   It's up to you whether to go or not.

7. to be at the post

   在職／在职  ―  zàizhí  ―  to be on the job; to be at one's post

   在野  ―  zàiyě  ―  to be out of office

8. Misspelling of 再 (zài).
9. a surname
10. (Hokkien) steady

    坐較在咧 [Hokkien, trad.]
    坐较在咧 [Hokkien, simp.]

    From: https://sutian.moe.edu.tw/zh-hant/su/2128/

    chē khah chāi leh [Pe̍h-ōe-jī]

    Sit a little more steadily.

11. (Singapore Hokkien) solid, confident, and collected under pressure; skilled

    伊真在咧 [Hokkien]  ―  i chin chāi leh [Pe̍h-ōe-jī]  ―  He's so talented!

• (to exist):

• (in):

• (during):

• (steady):

在穩／在稳 (chāi-ún), 穩定／稳定 (wěndìng)

→ English: zai (“skilled”)

在

1. (Hokkien) Alternative form of 佇 (“at, in”)

• “在”, in 漢語多功能字庫 (Multi-function Chinese Character Database)‎, 香港中文大學 (the Chinese University of Hong Kong), 2014–
• Dictionary of Chinese Character Variants (教育部異體字字典), A00743

(grade 5 “Kyōiku” kanji)

• Go-on: ざい (zai, Jōyō)
• Kan-on: さい (sai)
• Kun: ある (aru, 在る, Jōyō); あり (ari, 在り); あり (ari, 在); ます (masu, 在す); います (imasu, 在す)
• Nanori: あきら (akira); ひさし (hisashi); あき (aki); あり (ari); ありふく (arifuku); ある (aru); たもつ (tamotsu); ちえぼく (chieboku); みつる (mitsuru)

From Middle Chinese 在 (MC dzojX|dzojH). Attested in compounds since at least the 900s.[1]

• (Tokyo) ざ​い [záꜜì] (Atamadaka – [1])[2] — pitch is specific to use as a standalone noun
• IPA^(key): [d͡za̠i]

在(ざい) • (zai) 

1. [from at least 900s] (as used in compounds) at, in, located

在(ざい) • (zai) 

1. [from 1569] Clipping of 在郷 (zaigō): countryside or outskirts

Alternative spelling for 有り (ari), the Classical and Old Japanese copula.

在 (eumhun 있을 재 (isseul jae))

1. Hanja form^? of 재 (“exist”).

• 존재 (存在, jonjae, “existence”)

• 𠂇 (kwukyel abbreviation)

在 (*KYE-)

1. to exist, to be at

   Synonym: 有叱 (*Is-)

2. A common auxiliary verb or (more probably) verbal suffix, usually thought to denote the completive aspect, i.e. describing an action which has been completed and remains in such a state. An alternative but minority hypothesis holds that it honored the subject of the verb to a moderate degree, whereas 賜 (*-si) was more highly honorific.

• In both senses, it appears to have been wholly supplanted by the Middle Korean stage by 有叱 (*Is-) > Middle Korean 잇다〮 (ìstá), which is already more common for the independent verbal sense in the early first millennium and is first attested as an auxiliary in 1262. The word is not found in Middle Korean outside the two derived terms given below.

• Conventionally read as *KYE- because Middle Korean Idu script manuals, which commonly preserve Old Korean readings, read this character as 견 (kyen), which is clearly an inflected form with the realis gerund ㄴ (-n).
• Although Old Korean writing does not mark pitch, the Middle Korean reflexes show rising pitch, which are the result of a merger of a low-pitch and high-pitch syllable. This means that the Old Korean verb stem was not in fact monosyllabic *kye- but really consisted of two syllables. However, this original pronunciation cannot be reconstructed.

• ⇒ Middle Korean: 겨〯시다〮 (kyěsìtá, “to exist, to be at”, honorific)
  • Korean: 계시다 (gyesida)
• ⇒ Middle Korean: 겨〯집 (kyěcìp, “woman”, literally “stay-at-home”)
  • Korean: 계집 (gyejip)

• 이승재 [iseungjae] (2001) “古(고)代(대) 吏(이)讀(두)의 尊(존)敬(경)法(법) '在(재)[겨]'에 대하여 [On the deferential marker -kye- in Old Korean idu]”, in Eomun yeon-gu, volume 29, number 4, pages 53—70
• 남풍현 [nampunghyeon] (2004) “시상의 조동사 '在/𠂇/겨'의 발달' [sisang'ui jodongsa 在/𠂇/gyeo- ui baldal, The development of the aspectual auxiliary kye-]”, in Gugeo gukmunhak, volume 138, pages 5—34

在: Hán Việt readings: tại
在: Nôm readings: tại

1. in