BACILLUS / ba-SIL-lus / n. ; pl. -illi; etymology: New Latin, from Medieval Latin, small staff, rod, diminutive of Latin baculus staff, alteration of baculum, date: circa 1879
1: any of a genus (Bacillus) of aerobic rod-shaped gram-positive bacteria producing endospores that do not thicken the rod and including many saprophytes and some parasites (as B. anthracis of anthrax); broadly : a straight rod-shaped bacterium, a microscopic organism which causes disease. 2: a single-member project which produces sonic pathogens and infects hosts with noise.