viroid

noun

vi·​roid ˈvī-ˌrȯid 

: any of two families (Pospiviroidae and Avsunviroidae) of subviral particles that consist of a small single-stranded RNA arranged in a closed loop without a protein shell and that replicate in their host plants where they may or may not be pathogenic

Examples of viroid in a Sentence

Recent Examples on the Web

Like viruses, viroids reproduce by invading healthy cells and reprogramming them to duplicate the viroid’s genetic makeup instead of the cell’s own. —Daniel E. Slotnik, New York Times, 8 May 2023

For now, the problem of the hop latent viroid has largely fallen to growers themselves. —Dan Adams, BostonGlobe.com, 3 Dec. 2022

The agency has also found diseases known to occur in China, called pospiviroid and spindle tuber viroid, in seeds, as well as a few pests of significance: an immature wasp and a larval seed beetle. —Jon Emont and Jesse Newman, WSJ, 5 Sep. 2020

Word History

Etymology

vir(us) + -oid entry 1

First Known Use

1971, in the meaning defined above

Medical Definition

viroid

1 of 2 noun

vi·​roid ˈvī-ˌrȯid 

1

: a hypothetical symbiont resembling a virus that was formerly held to be present in cells, to be favorable to the host, and to tend to mutate to a virus

2

: any of two families (Pospiviroidae and Avsunviroidae) of subviral particles that consist of a small single-stranded RNA arranged in a closed loop without a protein shell and that replicate in their host plants where they may or may not be pathogenic

viroid

2 of 2 adjective

1

: caused by a virus

viroid pneumonia

2

: of or relating to viroids