io
/ˈaɪəʊ/noun, interjection
io is spelled I-O: 2 letters and 2 syllables. It appears 2.6 times per million words in written English, the 16,896th most frequent word form (wordfreq, 2021 data, counting Io, the name). As a noun, io means “A type of moth, the io moth” (English Wiktionary, September 2026). The plural of io is ios.
How many letters and syllables are in io?
| Letters | 2: I-O |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | 2.6 times per million words; the 16,896th most frequent word form |
| Wrong spellings searched | none measured in search |
| Rhymes with |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is io?
Io appears 2.6 times per million words in written English, the 16,896th most frequent word form in the list. The list counts every capitalisation together, so this includes Io, the name.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce io?
- /ˈaɪəʊ/
Io has 2 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-io.wav, Wikimedia Commons (author and licence on each file's page).
What rhymes with io?
2 words on PlainSpell end in the same sounds as io from its last stressed vowel (/aɪoʊ/):
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of io
- ios plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does io mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
A type of moth, the io moth.
noun
- 1
Initialism of input and output.
- 2
Initialism of indirect object.
- 3
Initialism of intelligence officer.
- 4
Initialism of incident officer.
- 5
Initialism of investigation officer.
- 6
Initialism of international organization.
adjective
- 1
Abbreviation of intraosseous.
interjection
- 1
rareAn exclamation of joy or triumph.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Where does io come from?
From New Latin, from Ancient Greek Ἰώ (Iṓ, “Io”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).