tau
UK/taʊ//taʊ/
tau noun: the letter Τ /τ in the Greek alphabet; being the nineteenth letter of the Classical and Modern Greek, and the twenty-first letter of the Old and Ancient Greek alphabets. Also the alternative form of taw.
Noun (1)
tau (plural taus)
- The letter Τ /τ in the Greek alphabet; being the nineteenth letter of the Classical and Modern Greek, and the twenty-first letter of the Old and Ancient Greek alphabets.
- A Τ-shaped object or sign; a Saint Anthony's cross, sometimes regarded as a sacred symbol.
- Nor ſhall we take in the myſticall Tau, or the Croſſe of our bleſſed Saviour, which having in ſome deſcriptions an Empedon or croſſing foot-ſtay, made not one ſingle tranſverſion.1658, Thomas Browne, “The Garden of Cyrus. […]. Chapter I.”, in Hydriotaphia, Urne-buriall, […] Together with The Garden of Cyrus, […], London: […] Hen[ry] Brome […], →OCLC, page 96
- The ankh symbol (☥).
- Synonyms:
- crux ansata
- Chiefly written τ: used to designate the nineteenth star (usually according to brightness) in a constellation.
- A measurement of the sensitivity of the value of an option to changes in the implied volatility of the price of the underlying asset.
- (includes a list of coordinate terms)
- Chiefly written τ: an irrational and transcendental constant representing the ratio of the circumference of a Euclidean circle to its radius, equal to twice the value of pi (2π; approximately 6.2831853071).
Proper noun (1) capitalized: TAU
TAU
- Initialism of Transvaal Agricultural Union.
Noun (2) capitalized: TAU
TAU (countable and uncountable, plural TAUs)
Proper noun (2) capitalized: Tau
Tau (plural Taus)
- A surname from Chinese.
Also used as
tau is also the alternative form of taw.
tau is also the ellipsis of tau protein.
tau is also the ellipsis of tau lepton or tau particle.
tau is also the ellipsis of tau meson.
tau meaning in Arabic, Malay and Thai
tau in Arabic
- the letter Τ / τ in the Greek alphabet
- تَاو tāw
tau in Malay
- the letter Τ / τ in the Greek alphabet
- tau
tau in Thai
- the letter Τ / τ in the Greek alphabet
- เทา tao
Synonyms of tau
Forms of tau
| Noun | |
|---|---|
| plural | taus |
| plural | TAUs |
| Proper noun | |
| plural | Taus |
Origin of tau
From Middle English tau, taue, from Latin tau, from Ancient Greek ταῦ (taû) and Hebrew תָּו (tav). Sense 7 was used by Joseph M. Lindenberg in 1991, and popularized by the American educator and entrepreneur Michael Hartl in a 2010 paper which explains that τ resembles π; and that τ is the Greek equivalent of t, the first letter of turn, and 2π corresponds to one turn of a circle with a radius of one unit. Sense 8.1 (“ellipsis of tau lepton or tau particle”) was coined by the American physicist Martin Lewis Perl (1927–2014) after the first letter of Ancient Greek τρίτον (tríton, “third”), since the tau lepton or tauon was the third charged lepton discovered.
Variant of Tao.
Words formed from tau
Phrases with tau
- Gau Tau
- Lan Tau
- Tau Day
- Tau Ceti
- tau suan
- tau bones
- Tau Cetan
- Tau Cetans
- Tau Cetian
- tau staffs
- tau staves
- Sha Tau Kok
13 more phrasesFewer phrases
Words that rhyme with tau
48 more rhymesFewer rhymes
Questions about tau
- What does tau mean?
- Tau means the letter Τ /τ in the Greek alphabet; being the nineteenth letter of the Classical and Modern Greek, and the twenty-first letter of the Old and Ancient Greek alphabets.
- What is tau in Arabic?
- Tau in Arabic is تَاو (tāw). See Tau meaning in Arabic.
- What part of speech is tau?
- Tau can be a noun or a proper noun.
- How do you pronounce tau?
- Tau is pronounced /taʊ/ (UK).
- What is the plural of tau?
- The plural of tau is taus.
Words near tau in the dictionary
Source and license
Adapted from Wiktionary: tau (page history and authors); TAU (page history and authors); Tau (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.
Last updated:
Pronunciation audio from Wikimedia Commons, each file under its own free license: En-us-tau.ogg.
Cite this entry: “tau.” Word.ws, https://word.ws/tau. Based on Wiktionary, CC BY-SA 4.0.