pi·cor·na·vi·rus 
(pē-kôrnə-vī′rəs, pĭ-)
(pē-kôrnə-vī′rəs, pĭ-)n. pl. pi·cor·na·vi·rus·es
Any of a group of very small viruses, including the enteroviruses and the rhinoviruses, that infect animals and consist of RNA surrounded by an icosahedral protein shell.
[PICO- + RNA + VIRUS.]