Spirillum

Part of speech: noun

Definitions

1. A type of rigid, spiral-shaped bacterium that is often found in water or soil and can exhibit motility using flagella
2. A genus of bacteria characterized by their corkscrew-like shape, commonly known for their role in various ecological niches
3. A spiral bacterium belonging to a group that is commonly found in aquatic environments and can be involved in infectious diseases

Etymology: "Spirillum" is a Latinized diminutive of "spira," the Latin word for "coil," and it names a whole genus of bacteria shaped like tight corkscrews. The word itself was coined as a scientific name rather than arising in everyday speech, so its path into English runs through the taxonomy of microbiology. The "-illum" ending is the familiar Latin diminutive, the same kind of ending that makes "ovum" into "ovulum" in some scientific coinages, and it signals "little coil." Latin "spira" is also the source of the English word "spire," as in the pointed top of a church tower, both ultimately tracing back to the idea of something wound or twisted. Taxonomists reached for classical roots like this when naming organisms that had only recently come under the microscope, so the word carries a precise physical description: a small spiral, seen under a lens, given a Latin name.