echovirushol: echovirus n. one of a group of about 30 RNA-containing viruses, originally isolated from the human intestinal tract, that were found to produce pathological changes in cells grows in culture, although they were not clearly associated with any specific disease. These viruses - ehich were accordingly termed enteric cytopathic human orphan viruses - are now thought to be the cause of nonspecific meningitis, many gastrointestinal and respiratory tract infections , and of many illnesses producing symptoms of the common cold. compare reovirus.