Virions

Part of speech: noun

Definitions

1. An individual viral particle is described as a small, infectious unit that includes genetic material and is surrounded by a protein layer
2. A complete viral structure is recognized as a particle that carries genetic information, protected by a protein coat, and capable of causing infection
3. A single infectious entity is defined as a viral particle containing nucleic acid and enclosed within a protective protein shell that can initiate infection in a host organism

Etymology: "Virions" is the plural of "virion", a noun for a single complete virus particle: a small infectious unit carrying genetic material inside a protein coat. The word came into English from French "virion", and its parts are "virus" plus the suffix "-on", which in chemistry and physics names a particle or unit, as in "electron" or "proton". So the word simply labels a virus particle in its complete, infectious form. The core of the word, "virus", is itself a Latin word meaning poison or slimy liquid, and it kept that general sense for centuries before scientists applied it to disease-causing agents. Coining "virion" came later, once researchers needed a term for the individual particle as distinct from the disease-causing agent in general.