boo
/buː/
"boo" is a 3-letter English headword indexed on PlainSpell.
The verdict
“boo” sits in 20 confusable pairs (corpus #8,014) as an interjection. The look-alike neighbours are the real trap.
- #8,014
- frequency rank, English
- 4,121
- “B” headwords
- 20
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A loud exclamation intended to scare someone. Usually used when one has been hidden from the target, and then appears unexpectedly.
Corpus desk
Index EN-boo · boo · English
boo · rank #8,014 · 0 variants · 20 confusables
- FREQ-COMMON #8,014
- LEN-MID 3 letters
- VOW-2 2 vowels
- CONFUS-HIGH 20 pairs
- VAR-0 0 variants
- BOOK-MID 4,121
- PHOTO-FINISH BMW
Nearest frequency peer: BMW (-1 rank slots)
Read with this headword: Spelling guide for this pattern
Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.
Frequency neighbourhood for “boo”
Lower corpus rank = more everyday usage (inverted bar length for readability)
- betty
betty
91,990 corpus weight
- biblical
biblical
91,989 corpus weight
- BMW
BMW
91,988 corpus weight
- boo
boo
91,987 corpus weight
- Cardiff
Cardiff
91,986 corpus weight
- coloured
coloured
91,984 corpus weight
What this shows Bars show where “boo” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | boo |
| Language | English |
| Part of speech | Interjection |
| IPA | /buː/ |
| Letters | 3 |
| Frequency rank | #8,014 |
| Misspellings tracked | 0 |
| Confusable pairs | 20 |
| Source | Wiktionary (kaikki.org) |
Where “boo” sits in English frequency
Easy to mix with look-alikes
The spelling risk for boo is neighbouring look-alikes ("by", "BS", …), not just typos; it is aninterjection pronounced /buː/. Frequency #8,014 among 4,121 “B” headwords. 2 recorded senses keep meaning in play.
boo doesn't appear in our generated misspelling index, and the word's spelling is regular enough that our generator found nothing worth flagging. It also participates in 20 confusable-pair relationships, "by", "BS", "br", and more, where similar look or sound leads writers to substitute one word for another in context.
Etymologically, the entry records: From earlier (15c.) boh, coined to create a loud and startling sound. Compare Middle English bus! (“bang!”, interjection), Latin boō (“cry aloud, roar, shout”, verb), Ancient Greek βοάω (boáō, “shout”, verb). The correct English form is boo, spelled B-O-O.
Definition
- 1A loud exclamation intended to scare someone. Usually used when one has been hidden from the target, and then appears unexpectedly.
- 2An exclamation used by a member of an audience, as at a stage play or sporting event, to indicate derision or disapproval.
Recorded use
Wiktionary exampleThese source excerpts show how boo appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
I ask them to record their votes in my favour, and I ask, is there any man who will dare to call me a stranger (hear, hear, and booing)?
Etymology
From earlier (15c.) boh, coined to create a loud and startling sound. Compare Middle English bus! (“bang!”, interjection), Latin boō (“cry aloud, roar, shout”, verb), Ancient Greek βοάω (boáō, “shout”, verb).
This word in other languages
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.
PlainSpell is rendered directly from structured Wiktionary extracts and open word-frequency lists, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of September 3, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.
Frequently Asked Questions
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Similar English words by spelling shape
Same letter count and similar misspelling depth for "boo", not the corpus desk frequency band.
What to do next
You've looked up "boo". Here's where to go from here.
- "boo" maps to 20 confusable pairs in this vintage; the highest-scored is "by". View pair
- Usage frequency rank #8,014 among English headwords in this corpus. Corpus statistics
- Browse more English words in the "B" letter cohort. B–Z browse
- PlainSpell rotates a curated Word of the Day from the English corpus, a passive way to discover vocabulary. Word of the Day
PlainSpell is a reference corpus, not spelling advice. Verify unusual forms in context.
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.