**Tēng-gī** sī tùi chi̍t hāng piáu-tat ê ké-soeh kiam sán-seng che ké-soeh ê khang-khòe. Siū tio̍h tēng-gī ê tùi-siòng kiò chò pī-tēng-gī-hāng (eng. *definiendum*), nā thê-kiong tēng-gī ê tîn-su̍t thang kiò tēng-gī-kù (*definiens*). Pí-lūn tī thâu-chêng ê tîn-su̍t lāi-té, "tēng-gī" chi̍t-ê jī-sû chiū sī pī-tēng-gī-hāng, nā āu-piah ê ké-soeh bûn-kù "sī tùi chi̍t hāng piáu-tat ê ké-soeh...", chiū sī tēng-gī-kù.

Hêng-sek
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### Si̍t-chāi kap miâ-gī tēng-gī

Tùi John Locke si̍t-chāi pún-chit (*real essence*) kap miâ-gī pún-chit (*nominal essence*) koan-liām lâi hoat-tián, thang kā tēng-gī khu-hun chhut si̍t-chāi kap miâ-gī nn̄g khoán. Bó͘ chi̍t iōng-gí ê si̍t-chāi tēng-gī sī su-iàu tiâu-cha mi̍h-kiāⁿ pún-sin lâi liáu-kái--ê; nā miâ-gī tēng-gī sī su-iàu óa-khò tiāu-cha hit jī ê ì-sù kap sú-iōng lâi liáu-kái.

### Jī-tián tēng-gī

Chi̍t hāng jī-tián-sek ê tēng-gī, sī siat-kè beh thê-kiong chhiong-chiok ê chu-sìn piáu-tat, lâi chè-chō tùi iōng-gí ê chi̍t chióng lí-kái. Chóng-sī pí-lūn nā tiat-ha̍k-kài tùi ēng-gí tēng-gī ê thó-lūn, it-poaⁿ m̄-sī jī-tián thang thê-kiong--ê.

### Iok-sok-sek tēng-gī

Iok-sok-sek (*stipulative*) tēng-gī sī chiam-tùi siū tēng-gī ê iōng-gí siat-tēng ì-sù, jî-chhiá m̄-bián chham-khó iōng-gí chá-chêng ê sú-iōng lí-lō͘. Pí-lūn nā kóng "*Jack the Ripper* sī bô͘-sat X, YX, Y kap ZZ ê lâng" chit khoán tîn-su̍t, pī-tēng-gī ê *Jack the Ripper* sī kò͘-tēng tùi-siòng ê lâng-miâ, m̄-koh āu-piah ê ké-soeh m̄-sī kò͘-tēng--ê, i bô hoat-tō͘ chin-chiàⁿ kap *Jack the Ripper* hō͘-siōng thè-ōaⁿ, só͘-í koh ài ka-thiam iok-sok ê tîn-su̍t ", nā sī hia bô͘-sat-àn sī choan-bûn chi̍t-ê lâng chhòng--ê" chìn chi̍t-pō͘ hān-tēng tùi-siòng.

### Kì-su̍t-sek tēng-gī

Kì-su̍t-sek (*descriptive*) tēng-gī, tû-liáu kóng-bêng ì-sù, mā beh móa-chiok kì-tēng ê sú-iōng. Pún khoán ê tēng-gī chiàu in móa-chiok ê thêng-tō͘ koh thang khu-hun chò saⁿ téng: gōa-chāi-sèng (*extensional*), lōe-chāi-sèng (*intensional*), kap kám-siū-sèng (*sense*).

### Ké-soeh-sek tēng-gī

Ké-soeh-sek (*explicative*) tēng-gī sī te̍k-pia̍t chun-siú bó͘ chi̍t iōng-gí chòe tiong-sim pō͘-hūn ê sú-iōng hong-sek, koh tùi gōa-gûi pō͘-hūn ēng iok-sok ê hêng-sek chhù-lí. Ké-soeh tēng-gī thang hông ēng tī chi̍t kóa put-oân-boán ê khài-liām.

Tēng-gī kap bûn-me̍h
--------------------

Tēng-gī ê tîn-su̍t su-iàu chiap-siū-chiá tùi tēng-gī-kù sū-sian ê liáu-kái, chiah thang thê-chhut thang tùi-tâng pī-tēng-gī-hāng ê tēng-gī-kù. Ū-ê tēng-gī khah pit-iàu óa-khò bûn-me̍h, ia̍h chiū sī pōe-kéng chu-sìn lâi chi-chhî, pí-lūn kóng "a-pah sī pē-bú lāi-bīn cha-po͘ hit--ê" chi̍t khoán tîn-su̍t. Koh-lâi ū chi̍t chióng tēng-gī, tēng-gī-kù lāi-bīn koh ēng tio̍h pī-tēng-gī-hāng, pí-lūn kóng "x sī y ê ti̍t-chiap chó͘-sian, nā kan-ta tng (*if and only if*) x sī y ê pē-bú he̍k-chiá x sī y ê ti̍t-chiap chó͘-sian" chi̍t khoán tîn-su̍t, tī tēng-gī-kù koh ēng tio̍h chi̍t pái pī-tēng-gī-hāng, chi̍t khoán chêng-hêng hō chò chài-kui (*recursive*).

Chham-chiàu
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1. 1 2  G. Longworth (2009). "Definitions: Uses and Varieties of". *Concise Encyclopedia of Philosophy of Language and Linguistic*. Elsevier Science. ISBN 9780080965017.
2. 1 2 3 4 5  Anil Gupta. "Definitions". *Stanford Encyclopedia of Philosophy*. The Metaphysics Research Lab. ISSN 1095-5054. 2017-05-07 khòaⁿ--ê.