bacterium
UK[bækˈtɪəriəm]US[bækˈtɪriəm]
n
A type of very small living thing that consists of a single cell, some types of which can cause disease.
Etymology
The word 'bacterium' is a modern Latin term, derived from the Greek 'baktērion', a diminutive of 'baktron', meaning "staff" or "stick". This nomenclature arose from the rod-like shape of the first bacteria observed under early microscopes. The scientific adoption of the term in the 19th century formalized it to describe a vast domain of microscopic, single-celled organisms. Thus, the modern abstract meaning for a fundamental biological category stems from a simple, ancient descriptor of its physical form.
Analysis
The word is a simplex loanword from Latin. It cannot be meaningfully segmented into productive English morphemes without altering its spelling or obscuring its origin.
Examples
A single bacterium can multiply rapidly under ideal conditions.
This antibiotic is effective against a wide range of harmful bacteria.
The bacterium responsible for the infection was identified through laboratory testing.