- any of a genus (Bacillus) of rod-shaped bacteria that occur in chains, produce spores, and are active only in the presence of oxygen
- any rod-shaped bacterium
- loosely any of the bacteria, esp. those causing disease
Origin of bacillusModern Latin ; from Late Latin little rod ; from Classical Latin bacillum, diminutive of baculus, variant, variety of baculum, a stick ; from Indo-European base an unverified form bak-, staff from source peg, Classical Greek baktron
- Any of various bacteria, especially a rod-shaped bacterium.
- Any of various rod-shaped, spore-forming, aerobic bacteria of the genus Bacillus that often occur in chains and include B. anthracis, the causative agent of anthrax.
Origin of bacillusLate Latin, diminutive of Latin baculum, rod; see bak- in Indo-European roots.
From Latin bacillus (“little staff, wand”).