Nu
Nu (Ν, ν) is the 13th letter of the Greek alphabet, said “noo” or “nyoo” and written n in Latin letters. In science the small ν stands for quantities such as a frequency or kinematic viscosity.
Easily confused with
How to read it
Dictionary.com gives the American pronunciation as “noo” or “nyoo”; the Collins English Dictionary gives British /njuː/, “nyoo”, and describes nu as a consonant transliterated as n. The capital Ν has the same shape as the Latin N, and the small ν looks much like a Latin v and the Greek Upsilon υ, but each is a separate character with its own code point in Unicode.
Also searched as: nu letter, nu symbol, ν, Ν.
Capital and small forms
| Form | Character | Code point | Unicode name |
|---|---|---|---|
| Capital | Ν | U+039D | GREEK CAPITAL LETTER NU |
| Small | ν | U+03BD | GREEK SMALL LETTER NU |
The Latin look-alikes are N (U+004E) and v (U+0076); the small upsilon υ is U+03C5.
Nu in science
The SI, the international system of units, defines the second with a frequency written with nu: Δν_Cs, the hyperfine transition frequency of the caesium 133 atom, is 9 192 631 770 Hz (NIST SP 330). NIST’s Guide for the Use of the SI gives ν as the symbol for kinematic viscosity, measured in square metres per second, beside η for dynamic viscosity.
Why the WHO skipped Nu
When the World Health Organization named the SARS-CoV-2 variant B.1.1.529 in November 2021, the next letter on its list was Nu. It went to Omicron instead, skipping Nu and Xi. The WHO told CNN that “Nu is too easily confounded with ‘new’”.
Write in Greek letters
stringmash.comGreek alphabet translatorWrite English in Greek letters by sound, or turn Greek back into Latin letters as Greek passports do.Read next
- Next in Greek lettersXiXi (Ξ, ξ) is the 14th letter of the Greek alphabet. It stands for the ks sound and is written x in Latin letters; English speakers say it “zye”, “sye” or “ksee”.
- In Statistics symbolsSample size (n N)n is the sample size, the number of values in a sample. A capital N usually stands for the size of the whole population, though some books use N for the number of values in the data instead.
More greek letters
The same shape elsewhere
Browse symbols drawn with letters and numbers.
Sources
- nu (Dictionary.com entry), Dictionary.com Unabridged; Collins English Dictionary, Dictionary.com, Entry, American and British (Collins) senses
- Greek and Coptic: Range 0370–03FF (code chart), The Unicode Standard, Version 18.0, Unicode Consortium, Greek capital and small letters
- C0 Controls and Basic Latin: Range 0000–007F (code chart), The Unicode Standard, Version 18.0, Unicode Consortium, Basic Latin
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811 (2008), National Institute of Standards and Technology, Sec. 8.8 Viscosity; Table 13
- The International System of Units (SI), NIST Special Publication 330 (2019), National Institute of Standards and Technology, Sec. 2.2, definition of the SI
- Why WHO skipped two letters of the Greek alphabet in naming Omicron, 29 November 2021, CNN, Article
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 30, 2026. How we research
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