- the 19th letter of the Greek alphabet (T, τ).
- the consonant sound represented by this letter.
- tav.
- tau lepton.
- 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.
- the 19th letter in the Greek alphabet (Τ, τ), a consonant, transliterated as t