omicron
/ˈɒmɪkɹɒn/
"omicron" is a 7-letter English headword indexed on PlainSpell.
The verdict
“omicron” is an uncommon English word, ranked #63,118 in English word frequency and used as a noun.
- #63,118
- frequency rank, English
- 7
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - 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 1...
| Property | Value |
|---|---|
| Headword | omicron |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈɒmɪkɹɒn/ |
| Letters | 7 |
| Frequency rank | #63,118 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “omicron” sits in English frequency
Spelling & Dictionary Insight
The English entry for omicron is 7 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈɒmɪkɹɒn/. Corpus data places it at rank #63,118 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. The dominant gloss from Wiktionary reads: "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 1...".
omicron doesn't appear in our generated misspelling index, since its letter sequence doesn't invite the usual edit-distance slips. No confusable counterpart is on file for this word, since nothing in our dataset looks or sounds close enough to cause mix-ups.
Etymologically, the entry records: 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 apparen… The correct English form is omicron, spelled O-M-I-C-R-O-N.
Definition
- 1The 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.
Etymology
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.
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Using “omicron”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is O-M-I-C-R-O-N - every other letter order is a misspelling in standard orthography.
- Say it as /ˈɒmɪkɹɒn/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Browse more English words and confusable pairs in the same reference. English words
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.