microbe

A minute life form; a microorganism, especially a bacterium that causes disease. Not in technical use.

A minute living being not distinguished, primarily, as to its animal or vegetable nature.

A microscopic organism; a microorganism; — particularly applied to bacteria and especially to pathogenic forms.

Any microorganism, but specially said of those microorganisms which are harmful types of bacteria.

a minute life form (especially a disease-causing bacterium); the term is not in technical use