Word.ws English Dictionary

nox

/ɛn əʊ ˈɛks/

nox noun: the period of darkness in each twenty-four hours; a night. Also the alternative form of NOx.

Noun (1)

nox (plural noctes or (deprecated) noxes or (proscribed) noces)

  1. The period of darkness in each twenty-four hours; a night.

Noun (2)

nox (plural nox)

  1. (rare) millilux (unit of illuminance)

Noun (3) capitalized: NOx

NOₓ

  1. Any of the various nitrogen oxides produced during combustion.
    • "The NOx and particulate reductions provide clean air in the cities and communities we serve. [...]"2020 December 16, Daniel Puddicombe, “Treated DMUs become greener and cleaner”, in Rail, page 46

Noun (4) capitalized: NOx

NOx (uncountable)

  1. (alternative, automotive performance) Alternative form of nox (“nitrous oxide”).

Proper noun capitalized: Nox

Nox

  1. (Roman) The Roman goddess of night.

Also used as

nox is also the alternative form of NOx.

nox is also the abbreviation of nitrous oxide.

Synonyms of nox

Forms of nox

pluralnoctes
plural proscribednoxes
plural proscribednoces
pluralnox

Plural of nox: noctes

Origin of nox

Learned borrowing from Latin nox, from Proto-Italic *nok⁽ʷ⁾ts, from Proto-Indo-European *nókʷts.

From Latin nox (“night; darkness”), by analogy with lux from Latin lūx (“light; daylight, day”). Doublet of night.

From N (“nitrogen”) + ox (“oxide”).

Questions about nox

What does nox mean?
Nox means the period of darkness in each twenty-four hours; a night.
What part of speech is nox?
Nox can be a noun or a proper noun.
How do you pronounce nox?
Nox is pronounced /ɛn əʊ ˈɛks/.
What is the plural of nox?
The plural of nox is noctes.

Words near nox in the dictionary

  1. nowthe
  2. nowts
  3. nowy
  4. Nowy Sącz
  5. Nowy Targ
  6. nox
  7. noxa
  8. noxacusis
  9. noxae
  10. noxal
  11. noxally

Source and license

Adapted from Wiktionary: nox (page history and authors); NOx (page history and authors); Nox (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-nox.ogg.

Cite this entry: “nox.” Word.ws, https://word.ws/nox. Based on Wiktionary, CC BY-SA 4.0.