¹ Source: wiktionary.com
Definition of Viroids
1. viroid [n] - See also: viroid
Medical Definition of Viroids
1. A group of pathogens comprising the smallest known agents of infectious disease. They are unencapsulated and are capable of replicating autonomously in susceptible cells. Positively identified viroids composed of single-stranded RNA have been isolated from higher plants, but the existence of DNA viroids pathogenic to animals is suspected. (12 Dec 1998)