Dictionary.com

bacillus

[ buh-sil-uhs ]
/ bəˈsɪl əs /
Save This Word!
See synonyms for: bacillus / bacilli on Thesaurus.com

noun, plural ba·cil·li [buh-sil-ahy]. /bəˈsɪl aɪ/.
any rod-shaped or cylindrical bacterium of the genus Bacillus, comprising spore-producing bacteria.
(formerly) any bacterium.
QUIZ
ARE YOU A TRUE BLUE CHAMPION OF THESE "BLUE" SYNONYMS?
We could talk until we're blue in the face about this quiz on words for the color "blue," but we think you should take the quiz and find out if you're a whiz at these colorful terms.
Question 1 of 8
Which of the following words describes “sky blue”?
Meet Grammar CoachWrite or paste your essay, email, or story into Grammar Coach and get grammar helpImprove Your Writing
Meet Grammar CoachImprove Your Writing
Write or paste your essay, email, or story into Grammar Coach and get grammar help

Origin of bacillus

1880–85; <Late Latin, variant of Latin bacillum (diminutive of baculum) staff, walking stick
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

How to use bacillus in a sentence

British Dictionary definitions for bacillus

bacillus
/ (bəˈsɪləs) /

noun plural -cilli (-ˈsɪlaɪ)
any rod-shaped bacterium, such as a clostridium bacteriumCompare coccus (def. 2), spirillum (def. 1)
any of various rodlike spore-producing bacteria constituting the family Bacillaceae, esp of the genus Bacillus

Word Origin for bacillus

C19: from Latin: a small staff, from baculum walking stick
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for bacillus (1 of 2)

bacillus
[ bə-sĭləs ]

n. pl. ba•cil•li (-sĭlī′)
Any of various rod-shaped, usually gram-positive aerobic bacteria of the genus Bacillus that often occur in chains and include Bacillus anthracis, the causative agent of anthrax.
Any of various bacteria, especially a rod-shaped bacterium.

Medical definitions for bacillus (2 of 2)

Bacillus

n.
A genus of rod-shaped gram-positive bacteria capable of producing endospores.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for bacillus

bacillus
[ bə-sĭləs ]

Plural bacilli (bə-sĭlī′)
Any of various pathogenic bacteria, especially one that is rod-shaped.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK