tau

American  

[tou, taw, tahv, tawv] / taʊ, tɔ, tɑv, tɔv /

noun

1. the 19th letter of the Greek alphabet (T,τ ).

2. the consonant sound represented by this letter.

3. tav.

4. Physics. Also tauon tau lepton.

5. Also called tau protein.  Biochemistry. a protein that is an important component of nerve cells, helping to maintain their function and structure: in the brain, distortions in the protein’s molecular shape is associated with the onset of Alzheimer’s disease.

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tau British  

/ taʊ, tɔː /

noun

1. the 19th letter in the Greek alphabet (Τ, τ), a consonant, transliterated as t

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Etymology

Origin of tau

1250–1300; Middle English < Latin < Greek taû < Semitic; tav

Example Sentences

In Alzheimer's disease, they may promote the buildup of beta-amyloid and tau proteins.

From Science Daily • Mar. 13, 2026

"These cells naturally have differences in tau processing, giving us confidence that the mechanisms we identified are relevant to human disease."

From Science Daily • Mar. 3, 2026

The goal was to map the internal systems that control how tau accumulates inside brain cells.

From Science Daily • Mar. 3, 2026

When the researchers disrupted these energy-producing structures, cells began producing a specific tau fragment measuring about 25 kilodaltons.

From Science Daily • Mar. 3, 2026

Instead, the limited evidence now available suggests that T. tau and T. upsilon are names based on a highly variable character of color pattern of the head, and that only one species is involved.

From The Amphibians and Reptiles of Michoacán, México by Duellman, William E.