omicron
UK/ˈɒmɪkɹɒn//ˈoʊməˌkɹɑn/
omicron noun: the 15th letter of the Classical and Modern Greek alphabets (16th in Ancient and Old Greek), used in ordering lists as in naming (astronomy) the 15th star of a constellation or (epidemiology) the 15th discovered major variant of a disease. Also the ellipsis of Omicron variant.
Noun (1)
omicron (plural omicrons or omicra)
- The 15th letter of the Classical and Modern Greek alphabets (16th in Ancient and Old Greek), used in ordering lists as in naming (astronomy) the 15th star of a constellation or (epidemiology) the 15th discovered major variant of a disease.
- Your Majestie knows that unfortunate I [...] was the first who when I published my Poem of Italia Liberata endeavoured to bring the Omicron, Eupselon, Omega, and other Greek Letters, which I thought very requisite for that language, into my own Tongue;1656 [1612], Henry, Earl of Monmouth, transl., I Raggvagli di Parnasso: or Advertisements from Parnassus, London: Humphrey Moseley, translation of De Ragguagli di Parnaso by Traiano Boccalini, page...
- The E serves both for the Epsilon and Eta; the O, both for the Omicron and Omega, and likewise for the diphthong OΥ.1750 [1748 January 10], James Russel, “Letter LI”, in Letters from a Young Painter Abroad to his Friends in England, volume II, London: W. Russel, page 120
Noun (2) capitalized: Omicron
Omicron (uncountable)
- Ellipsis of Omicron variant.
Noun (3) capitalized: Omicron
Omicron (plural Omicrons or Omicra)
- Alternative form of omicron (Greek letter) (especially in the majuscule form)
Proper noun capitalized: Omicron
Omicron
- Ellipsis of Omicron Hill: a mountain in North Slope borough, Alaska, United States.
Also used as
omicron is also the ellipsis of Omicron variant.
omicron meaning in Arabic, Malay and Thai
omicron in Arabic
- Greek letter
- أُومِيكْرُون ʔumikrūn
omicron in Malay
- Greek letter
- omikron
omicron in Thai
- Greek letter
- โอไมครอน oo-mai-krɔ̂n
Forms of omicron
| plural | omicrons |
|---|---|
| plural | omicra |
| alternative form | Omicron |
| alternative form | omikron |
| alternative form | Omikron |
| alternative form | o |
| alternative form | O |
| alternative form | Ο |
| alternative form | ο |
| plural | Omicrons |
| plural | Omicra |
Origin of omicron
From Latin omicron, from Koine Greek ὂ μῑκρόν (ò mīkrón, “little o”), named in contrast with omega (“big o”). The uncommon form omicra is similarly borrowed from Latin and Greek. The use for designating stars in a constellation—typically in order of apparent brightness—began with Johann Bayer's 1603 Uranometria.
Words formed from omicron
Words that rhyme with omicron
Questions about omicron
- What does omicron mean?
- Omicron means the 15th letter of the Classical and Modern Greek alphabets (16th in Ancient and Old Greek), used in ordering lists as in naming (astronomy) the 15th star of a constellation or (epidemiology) the 15th discovered major variant of a disease.
- What is omicron in Arabic?
- Omicron in Arabic is أُومِيكْرُون (ʔumikrūn). See Omicron meaning in Arabic.
- What part of speech is omicron?
- Omicron can be a noun or a proper noun.
- How do you pronounce omicron?
- Omicron is pronounced /ˈɒmɪkɹɒn/ (UK).
- What is the plural of omicron?
- The plural of omicron is omicrons.
Words near omicron in the dictionary
Source and license
Adapted from Wiktionary: omicron (page history and authors); Omicron (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-omicron-2.ogg.
Cite this entry: “omicron.” Word.ws, https://word.ws/omicron. Based on Wiktionary, CC BY-SA 4.0.