“+ noun
Etymology: International Scientific Vocabulary micr- + organism
: an organism of microscopic or ultramicroscopic size — used especially of bacteria and protozoa
soil-inhabiting microorganisms — S.A.Waksman
Synonyms:
germ , microbe , bacterium , bacillus , virus , pathogen : microorganism is the general term for any organism of microscopic or ultramicroscopic size. germ and microbe are early nonscientific synonyms for microorganism. germ often refers to microorganisms regarded as a source or origin (as of a disease)
typhus germs
It is often used to indicate a rudimentary beginning or embryo capable of evolving or developing
germs of the doctrine of which he is the founder may be traced to much earlier, even ancient periods — Encyc. Americana
microbe may be somewhat more awesome than germ and is rarely used with pleasing suggestion
the late stage of true invasion of the tissues around the brain and spinal cord by the deadly microbes — F.G.Slaughter
bacterium is now the common scientific designation for a large group of microscopic plants with single-celled or acellular bodies of various forms that affect the life of man in various ways. bacteria is sometimes used to designate rod-shaped bacteria that do not form endospores and is contrasted with bacillus in its narrow sense. bacillus in science refers to any straight rod-shaped bacterium or to any straight aerobic rod-shaped bacterium that forms endospores; popularly it refers to various disease-causing bacteria
the bacilli of diphtheria
virus technically indicates a submicroscopic infective agent sometimes considered as composed of complex protein molecules capable of growth in living cells
polio virus
virus is applicable to any dread, insidious, inexorable agent
right in claiming that the virus of Pan-Germanism and Nazism was present in the speeches — Times Literary Supplement
pathogen is applicable to any living agent that causes disease (as a bacterium, virus, fungus, or worm); it stresses this aspect and implies nothing about relative size, being freely applied to agencies that are not microorganisms
many pathogens attack a vigorous host most readily — Science