bacillus •Callas, callous, callus, Dallas, Pallas, phallus •Nablus • manless •hapless, mapless •atlas, fatless, hatless •braless, parlous •armless • artless •jealous, zealous •endless • legless • sexless • airless •talus • bacillus • windlass • Nicklaus •obelus • strobilus •acidophilus, Theophilus •angelus • Aeschylus • perilous •scurrilous • Wenceslas • nautilus •Silas, stylus •jobless •godless, rodless •Patroclus • topless • coxless •lawless, oarless •Aeolus, alveolus, bolas, bolus, gladiolus, holus-bolus, solus, toeless •Troilus • Douglas • useless • Tibullus •garrulous • querulous • fabulous •miraculous • calculus • famulus •crapulous • patulous • nebulous •credulous, sedulous •pendulous • regulus •emulous, tremulous •bibulous • acidulous •meticulous, ridiculous •mimulus, stimulus •scrofulous • flocculus • Romulus •populace, populous •convolvulus •altocumulus, cirrocumulus, cumulus, stratocumulus, tumulus •scrupulous •furunculous, homunculus, ranunculus •Catullus • troublous •gunless, sunless •cutlass, gutless •earless • Heliogabalus •libellous (US libelous) • discobolus •scandalous • Daedalus • astragalus •Nicholas • anomalous • Sardanapalus •tantalus •marvellous (US marvelous) •frivolous • furless • surplus

Bacillus A genus of bacteria in which the cells are rod-shaped, often motile, and typically Gram-positive. Endospores can be formed in the presence of air. Bacillus species are chemo-organotrophic. Some can grow only in the presence of air; others can grow in either the presence or absence of air. There are many species, found in a wide range of habitats. Some species can cause disease in vertebrate animals (e.g. anthrax), or in insects; insecticidal species, particularly B. thuringiensis, are used in the biological control of insect pests.

ba·cil·lus / bəˈsiləs/ • n. (pl. -cil·li / -ˈsilī/ ) a disease-causing bacterium. ∎  a rod-shaped bacterium. DERIVATIVES: bac·il·lar·y / ˈbasəˌlerē/ adj. ORIGIN: late 19th cent.: from late Latin, diminutive of Latin baculus ‘stick.’

bacillus Any rod-shaped bacterium. Generally, bacilli are large, Gram-positive, spore-bearing, and have a tendency to form chains and produce a capsule. Some are motile, bearing flagella. They are ubiquitous in soil and air and many are responsible for food spoilage. The group also includes Bacillus anthracis, which causes anthrax.

bacillus (bă-sil-ŭs) n. (pl. bacilli) any rod-shaped bacterium. See also Bacillus, Lactobacillus, Streptobacillus.