Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

bacillus

play
noun ba·cil·lus \bə-ˈsi-ləs\

Simple Definition of bacillus

  • : a straight rod-shaped bacterium that requires oxygen for growth; also : a bacterium that causes disease

Full Definition of bacillus

plural ba·cil·liplay \-ˌlī also -lē\

  1. 1 :  any of a genus (Bacillus) of rod-shaped gram-positive usually aerobic bacteria producing endospores and including many saprophytes and some parasites (as B. anthracis of anthrax); broadly :  a straight rod-shaped bacterium

  2. 2 :  bacterium; especially :  a disease-producing bacterium

Origin of bacillus

New Latin, from Medieval Latin, small staff, rod, diminutive of Latin baculus staff, alteration of baculum


First Known Use: 1868

Rhymes with bacillus


Medical Dictionary

bacillus

play
noun ba·cil·lus \bə-ˈsil-əs\

Medical Definition of bacillus

plural ba·cil·li \-ˌī also -ē\play

  1. 1a capitalized :  a genus of rod-shaped gram-positive endospore-producing usually aerobic bacteria of the family Bacillaceae that include many saprophytes and some parasites (as B. anthracis of anthrax)b:  any bacterium of the genus Bacillus; broadly :  a straight rod-shaped bacterium

  2. 2:  bacterium; especially :  a disease-producing bacterium





Seen and Heard

What made you want to look up bacillus? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

February 7, 2016

a slight offense

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image1037863653

Which of the following refers to thin, bending ice, or to the act of running over such ice?

pince-nez kittly-benders spindrift duvet
Name That Thing

10 quick questions: hear them, spell them, and see how your skills compare to the crowd.

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ