theta

See also: Theta, théta, thèta, thêta, and þeta

English

Ancient Greek alphabet

← eta		→ iota
Θ θ Ancient Greek: θῆτα
Wikipedia article on theta

Etymology

Borrowed from Ancient Greek θῆτα (thêta).

Pronunciation

• (UK) IPA^(key): /ˈθiːtə/
• (US, Canada) IPA^(key): /ˈθeɪtə/, [ˈθeɪɾə], /ˈθitə/

  • Audio (California):

    (file)

• (General Australian, New Zealand) IPA^(key): /ˈθæɪtə/, [ˈθæɪɾə]
• (Hong Kong) IPA^(key): /ˈθeɪ.ta/, [fei̯˥ tʰaː˩]
• Rhymes: -iːtə, -eɪtə

Noun

theta (plural thetas)

1. The eighth letter of the Modern Greek alphabet, ninth in Old Greek: Θ, θ.
2. (mathematics) The measure of an angle.
3. (aviation, by extension) Pitch angle; the angle between an aircraft's longitudinal axis and the horizontal plane.

   Synonym: deck angle

4. (finance) The sensitivity of the value of a derivative with respect to time; the "time decay".
5. (biology) Designating a level of brain activity as measured by electroencephalography having a frequency of between four and seven cycles per second (associated with drowsiness in adults).
   • 2018 September 19, Meghan O'Gieblyn, “The Most Unread Book Ever Acclaimed”, in The Paris Review:

     The reader is less likely to throw the book down in a fit of disgust than she is to be lulled into a theta state, a highway hypnosis induced by page after page of incantatory prose.

6. (phonology) The voiceless dental fricative represented by θ.

Hypernyms

• (measure of derivative price sensitivity): Greeks (includes list of coordinate terms)

Coordinate terms

(pitch angle of an aircraft):

• alpha
• beta
• gamma

Derived terms

• antitheta
• entheta
• Ramanujan theta function
• theta-delta
• thetaform
• theta function
• theta graph
• theta join
• theta meditation
• thetan
• theta pinch
• thetaprobe
• theta rhythm
• theta role
• thetatron
• theta wave

Descendants

• → Malay: teta

Translations

Greek letter

• Arabic: ثِيتَا f (ṯītā)

  Hijazi Arabic: ثيتا f (ṯīta)

• Aramaic: ܛܝܬܐ (ṯita)
• Armenian: թետա (tʻeta)
• Asturian: theta (ast)
• Catalan: theta (ca) f
• Chinese:

  Mandarin: 西塔 (zh) (xītǎ)

• Danish: theta (da) n
• Dutch: thèta (nl) m or f
• Esperanto: teto (eo)
• Finnish: theeta (fi)
• French: thêta (fr) m
• Georgian: please add this translation if you can
• German: Theta (de) n
• Greek: θήτα (el) n (thíta)

  Ancient Greek: θῆτα (thêta)

• Hebrew: טֵיתָא f (téta)
• Hungarian: théta (hu)
• Icelandic: þeta
• Interlingua: theta
• Japanese: テータ (ja) (tēta), シータ (ja) (shīta)
• Korean: 테타 (teta)
• Malay: teta
• Māori: heitā
• Marathi: थीटा n (thīṭā), थेटा n (theṭā)
• Polish: theta (pl) f
• Portuguese: teta (pt) m
• Russian: те́та (ru) f (tɛ́ta), фи́та (ru) f (fíta) (modern Greek)
• Spanish: zeta (es) f, theta (es) f, tita (es) f
• Swedish: theta (sv)
• Tagalog: teta
• Turkish: teta
• Ukrainian: те́та f (téta)

See also

• (Greek-script letter names) alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, xi, omicron, pi, rho, sigma, tau, upsilon, phi, chi, psi, omega

Catalan

Etymology

Borrowed from Ancient Greek θῆτα (thêta).

Pronunciation

• IPA^(key): (Northern) [ˈte̞.tə]
• IPA^(key): (Balearic, Central) [ˈtɛ.tə]
• IPA^(key): (Valencia, Northwestern) [ˈte.ta]

Noun

theta f (plural thetes)

1. theta; the Greek letter Θ (lowercase θ)

Further reading

• “theta”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007
• “theta”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2026
• “theta” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.

Czech

Alternative forms

• théta

Etymology

Borrowed from Ancient Greek θῆτα (thêta).

Pronunciation

• IPA^(key): [ˈtxɛːta]
• IPA^(key): [ˈtɛːta]

Noun

theta n or f

1. theta (Greek letter)

Declension

when feminine:

Declension of theta (hard feminine)

	singular	plural
nominative	theta	thety
genitive	thety	thet
dative	thetě	thetám
accusative	thetu	thety
vocative	theto	thety
locative	thetě	thetách
instrumental	thetou	thetami

Indeclinable when neuter.

Italian

Etymology

From the Ancient Greek θῆτα (thêta).

Pronunciation

• IPA^(key): /ˈtɛ.ta/
• Rhymes: -ɛta
• Hyphenation: thè‧ta

Noun

theta m or f (invariable)

1. theta (Greek letter)

Pali

Alternative forms

Alternative scripts

• 𑀣𑁂𑀢 (Brahmi script)
• थेत (Devanagari script)
• থেত (Bengali script)
• ථෙත (Sinhalese script)
• ထေတ (Burmese script)
• เถต or เถตะ (Thai script)
• ᨳᩮᨲ (Tai Tham script)
• ເຖຕ or ເຖຕະ (Lao script)
• ថេត (Khmer script)
• 𑄗𑄬𑄖 (Chakma script)

Adjective

theta

1. reliable
2. trustworthy

Polish

Etymology

Learned borrowing from Ancient Greek θῆτα (thêta), from Phoenician 𐤈 (ṭ‬ /⁠ṭēt⁠/).

Pronunciation

• IPA^(key): /ˈtɛ.ta/

• Audio:

  (file)

• Rhymes: -ɛta
• Syllabification: the‧ta

Noun

theta f

1. theta (Greek letter Θ, θ)

Declension

Declension of theta

	singular	plural
nominative	theta	thety
genitive	thety	thet
dative	thecie	thetom
accusative	thetę	thety
instrumental	thetą	thetami
locative	thecie	thetach
vocative	theto	thety

Further reading

• “theta”, in Polish dictionaries at PWN‎^[1] (in Polish)

Portuguese

Noun

theta f (plural thetas)

1. pre-reform spelling (used until 1943 in Brazil and 1911 in Portugal) of teta

Spanish

Etymology

Borrowed from Ancient Greek θῆτα (thêta).

Pronunciation

• IPA^(key): /ˈteta/ [ˈt̪e.t̪a]
• Rhymes: -eta
• Syllabification: the‧ta

Noun

theta f (plural thetas)

1. theta; the Greek letter Θ, θ

   Synonyms: zeta, tita