bacillus
/bæˈsɪl.əs/noun
bacillus is spelled B-A-C-I-L-L-U-S: 8 letters and 3 syllables. It appears about once in every 2 million words in written English, the 41,660th most frequent word form (wordfreq, 2021 data). As a noun, bacillus means “Any of various rod-shaped, spore-forming aerobic bacteria in the genus Bacillus, some of which cause disease” (English Wiktionary, September 2026). The plural of bacillus is bacilli.
How many letters and syllables are in bacillus?
| Letters | 8: B-A-C-I-L-L-U-S |
|---|---|
| Syllables | 3 (from its American pronunciation) |
| In writing | about once in every 2 million words; the 41,660th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is bacillus?
Bacillus appears about once in every 2 million words in written English, the 41,660th 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 bacillus?
- /bæˈsɪl.əs/
Bacillus has 3 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vininn126-bacillus.wav, Wikimedia Commons (author and licence on each file's page).
Forms of bacillus
- bacilli plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does bacillus mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
Any of various rod-shaped, spore-forming aerobic bacteria in the genus Bacillus, some of which cause disease.
- 2
Any bacilliform (rod-shaped) bacterium.
- 3
Something which spreads like bacterial infection.
The “bacillus of boom or depression,” he wrote, travels freely “from country to country.”
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Bacillus in Spanish, French, German and Portuguese
In the sense any bacteria in the genus Bacillus:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does bacillus come from?
Learned borrowing from Latin bacillus (“little staff, wand”), diminutive of baculum (“stick, staff, walking stick”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).