definitions

bacillus

[ buh-sil-uh s ]
/ bəˈsɪl əs /
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SEE MORE SYNONYMS FOR bacillus 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.

RELATED WORDS

microorganism, germ, virus, bug, bacterium, bacillus, pathogen, illness, ailment, sickness, disease, infection, microbe, crud, plague, germs

Nearby words

bacilli, bacilliform, bacillin, bacillosis, bacilluria, bacillus, bacillus calmette-guérin, bacillus cereus, bacillus sphaericus, bacillus thuringiensis, bacitracin

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. 2019

Examples from the Web for bacilli

British Dictionary definitions for bacilli

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

Medicine definitions for bacilli (1 of 2)

bacillus

[ bə-sĭl′əs ]

n. pl. ba•cil•li (-sĭl′ī′)

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.

Medicine definitions for bacilli (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.

Science definitions for bacilli

bacillus

[ bə-sĭl′əs ]

Plural bacilli (bə-sĭl′ī′)

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.

Culture definitions for bacilli

bacilli

[ (buh-sil-eye) ]

sing. bacillus

One of three forms of bacteria, usually rod-shaped.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.