acute contagious infection caused by the bacterium Corynebacterium diphtheriae; marked by the formation of a false membrane in the throat and other air passages causing difficulty in breathing
(virology) ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein
a software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer; "a true virus cannot spread to another computer without human assistance"
a harmful or corrupting agency; "bigotry is a virus that must not be allowed to spread"; "the virus of jealousy is latent in everyone"
(astronomy) any of the nine large celestial bodies in the solar system that revolve around the sun and shine by reflected light; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto in order of their proximity to the sun; viewed from the constellation Hercules, all the planets rotate around the sun in a counterclockwise direction
any celestial body (other than comets or satellites) that revolves around a star