the smallest of viruses; a plant virus with its RNA arranged in a circular chromosome without a protein coat
同义词：virusoid
viroid详细解释
vi.roid n.（名词）An infectious particle, similar to but smaller than a virus, that consists solely of a strand of RNA and is capable of causing disease in plants.类病毒：一种传染性微粒，与病毒相象但比病毒小，由核糖核酸单链构成，能在植物中引起疾病
