O'Brien
/əˈbɹaɪən/
"o-brien" is a 6-letter English headword indexed on PlainSpell.
The verdict
“O'Brien” is a regularly-used English word, ranked #8,964 in English word frequency and used as a proper noun.
- #8,964
- frequency rank, English
- 7
- letters
- 9
- tracked misspellings
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A surname from Irish.
| Property | Value |
|---|---|
| Headword | O'Brien |
| Language | English |
| Part of speech | Proper noun |
| IPA | /əˈbɹaɪən/ |
| Letters | 7 |
| Frequency rank | #8,964 |
| Misspellings tracked | 9 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “O'Brien” sits in English frequency
Spelling & Dictionary Insight
The English entry for O'Brien is 7 letters long, classified as a proper noun, and transcribed in the International Phonetic Alphabet as /əˈbɹaɪən/. Corpus data places it at rank #8,964 in overall English word frequency, indicating it appears regularly in written and spoken text. Wiktionary records 7 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 9 likely wrong-spelling variants for O'Brien, with forms such as "'obrien", "o'bbrien", and "o'biren". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. We don't track a confusable pairing for this entry, suggesting its spelling stands apart enough that readers rarely confuse it with something else.
Etymologically, the entry records: Anglicisation of the Irish surname Ó Briain, meaning “descendant of Brian”. The correct English form is O'Brien, spelled O-'-B-R-I-E-N.
Definition
- 1A surname from Irish.
- 2A number of places in the United States:
- 3A number of places in the United States:
- 4A number of places in the United States:
- 5A number of places in the United States:
- 6A number of places in the United States:
- 7A town in Buenos Aires province, Argentina, also known as Eduardo O'Brien.
Etymology
Anglicisation of the Irish surname Ó Briain, meaning “descendant of Brian”.
Common misspellings
Also misspelled as: 'obrien,o'bbrien,o'biren,o'brein,o'brienn,o'brine,o'brrien,o'rbien,ob'rien
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of O'Brien - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.
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
How do you spell "O'Brien"?
What does "O'Brien" mean?
What are common misspellings of "O'Brien"?
How do you pronounce "O'Brien"?
What is the origin of the word "O'Brien"?
Is PlainSpell free to use?
Using “O'Brien”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is O-'-B-R-I-E-N - every other letter order is a misspelling in standard orthography.
- Say it as /əˈbɹaɪən/ (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.