oo
/ˈoʊ.oʊ/noun, interjection
oo is spelled O-O: 2 letters and 2 syllables. It appears 3.7 times per million words in written English, the 13,496th most frequent word form (wordfreq, 2021 data). As a noun, oo means “Any of four Hawaiian birds of the genus Moho, formerly classed with the honeyeaters and now believed to be extinct” (English Wiktionary, September 2026). The plural of oo is oos.
How many letters and syllables are in oo?
| Letters | 2: O-O |
|---|---|
| Syllables | 2 (from its pronunciation) |
| In writing | 3.7 times per million words; the 13,496th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is oo?
Oo appears 3.7 times per million words in written English, the 13,496th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce oo?
- UK /ˈəʊ.əʊ/
- US /ˈoʊ.oʊ/
As an interjection (“Alternative form of ooh”): /uː/.
Oo has 2 syllables (counted from the pronunciation).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-oo-.wav, LL-Q1860_(eng)-Vealhurl-oo-2.wav, Wikimedia Commons (author and licence on each file's page).
Words people confuse with oo
Also written: ooh.
Sources: English Wiktionary (homophones, alternative spellings).
Forms of oo
- oos plural
- oö-
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does oo mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
Any of four Hawaiian birds of the genus Moho, formerly classed with the honeyeaters and now believed to be extinct.
- 2
obsolete(Ω, ω) The Greek letter omega.
noun
- 1
Alternative letter-case form of oo.
adjective
- 1
Initialism of object-oriented.
symbol
- 1
A dictionary transcription for the FOOT vowel, used i.a. in The American Heritage Dictionary of the English Language
symbol
- 1
A dictionary transcription for the GOOSE vowel, used i.a. in The American Heritage Dictionary of the English Language
interjection
- 1
Alternative form of ooh.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Where does oo come from?
From Hawaiian ʻōʻō, resembling its call.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).