1) French word used in English 2) Particle 
The infectious unit of a virus. 
an entire virus particle, consisting of an outer protein shell called a capsid and an inner core of nucleic acid (either ribonucleic or ... [4 related articles]
<virology> A single virus particle, complete with coat. ... (13 Oct 1997) ... 
(vi´re-on) a complete viral particle, found extracellularly and capable of surviving in crystalline form and infecting a living cell; it comprises the nucleoid (genetic material) and the capsid.
a complete virus particle.
The mature virus, the ultimate phase of viral development. The virion is either a naked or an enveloped nuclecapsid.A single virus particle, complete with coat.
Type: Term Pronunciation: vī′rē-on, vir′ē-on Definitions: 1. The complete virus particle that is structurally intact and infectious.
Virion: A complete virus particle with its DNA or RNA core and protein coat as it exists outside the cell. Also called a viral particle.
A virus particle existing freely outside a host cell.
[n] - a complete viral particle
a mature infectious virus particle existing outside a cell. 
inert particle that is the reproductive form of a virus
noun (virology) a complete viral particle; nucleic acid and capsid (and a lipid envelope in some viruses)