bool
"bool" is a 4-letter English headword indexed on PlainSpell.
The verdict
“bool” is uncommon English (frequency #56,624 among 4,121 “B” headwords), classed as a noun. The kind of spelling people second-guess.
- #56,624
- frequency rank, English
- 4,121
- “B” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A Boolean variable (one whose value is either true or false).
Corpus desk
Index EN-bool · bool · English
bool · rank #56,624 · 0 variants · 0 confusables
- FREQ-RARE #56,624
- LEN-MID 4 letters
- VOW-2 2 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 4,121
- PHOTO-FINISH Borisov
Nearest frequency peer: Borisov (+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.
Long-tail ranks near “bool”
Sparse band: bars invert rank so rarer forms read shorter
- blithely
blithely
43,384 corpus weight
- bloodlust
bloodlust
43,381 corpus weight
- blotter
blotter
43,380 corpus weight
- bool
bool
43,377 corpus weight
- Borisov
Borisov
43,376 corpus weight
- Brabant
Brabant
43,374 corpus weight
What this shows Long-tail view: where “bool” sits against similarly uncommon English ranks.
| Property | Value |
|---|---|
| Headword | bool |
| Language | English |
| Part of speech | Noun |
| Letters | 4 |
| Frequency rank | #56,624 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “bool” in English
Rare enough to double-check
bool is uncommon English at frequency #56,624 among 4,121 “B” headwords, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "A Boolean variable (one whose value is either true or false).".
bool has no tracked misspelling variants, a sign its spelling follows regular English conventions. It is not paired with a close-neighbour confusable in our dataset, which typically means the spelling is too distinctive to be mistaken for another word.
Etymologically, the entry records: From a keyword in C++ and derived programming languages, short for Boolean. The correct English form is bool, spelled B-O-O-L.
Definition
- 1A Boolean variable (one whose value is either true or false).
Recorded use
Wiktionary examplesThese source excerpts show how bool appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
The base class BitArray acts just like a normal C++ array of bools, although you are of course free to interpret the bits as integers […]
With an automatic conversion, bools will interfere with overload resolution […]
Etymology
From a keyword in C++ and derived programming languages, short for Boolean.
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 "bool"?
What does "bool" mean?
What is the origin of the word "bool"?
Is PlainSpell free to use?
Similar English words by spelling shape
Same letter count and similar misspelling depth for "bool", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 4 letters (nearest by frequency rank).