bacilli

/bəˈsɪl.aɪ/

//bəˈsɪl.aɪ// noun

"bacilli" is a 7-letter English headword indexed on PlainSpell.

The verdict

“bacilli” is uncommon English (frequency #95,718 among 31,241 “B” headwords), classed as a noun. The kind of spelling people second-guess.

#95,718
frequency rank, English
31,241
“B” headwords

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - plural of bacillus

Corpus desk

Index EN-bacilli · bacilli · English

bacilli · rank #95,718 · 0 variants · 0 confusables

  • FREQ-RARE #95,718
  • LEN-LONG 7 letters
  • VOW-3 3 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-DENSE 31,241
  • PHOTO-FINISH backbeat

Nearest frequency peer: backbeat (+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 “bacilli”

Lower corpus rank = more everyday usage (inverted bar length for readability)

corpus weight

What this shows Bars show where “bacilli” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.

Source FrequencyWords open word-frequency list As of May 6, 2026
Key facts for bacilli
PropertyValue
Headwordbacilli
LanguageEnglish
Part of speechNoun
IPA/bəˈsɪl.aɪ/
Letters7
Frequency rank#95,718
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “bacilli” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). bacilli lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Rare enough to double-check

bacilli is uncommon English at frequency #95,718 among 31,241 “B” headwords, classed as anoun, transcribed /bəˈsɪl.aɪ/. Rarity is why readers land here mid-draft. Gloss: "plural of bacillus".

Our edit-distance generator produced no likely misspellings for bacilli, typically a sign the spelling maps closely to how the word sounds. Our confusable-pair dataset has no match for it, since nothing in our dataset looks or sounds close enough to cause mix-ups.

This headword's origin isn't recorded in our source data, so spelling patterns must be inferred from the word's phoneme-to-grapheme mapping rather than from a documented borrowing chain. The correct English form is bacilli, spelled B-A-C-I-L-L-I.

Definition

  1. 1
    plural of bacillus

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 May 6, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.

Frequently Asked Questions

How do you spell "bacilli"?
"bacilli" is spelled B-A-C-I-L-L-I. The IPA pronunciation is /bəˈsɪl.aɪ/.
What does "bacilli" mean?
As a noun, "bacilli" means: plural of bacillus
How do you pronounce "bacilli"?
The IPA (International Phonetic Alphabet) transcription for "bacilli" is /bəˈsɪl.aɪ/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "bacilli" come from?
"bacilli" is a English word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "bacilli", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 7 letters (nearest by frequency rank).

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.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list