Final answer:
Vestibular neuritis is the dysfunction in the semicircular canals caused by a viral infection, leading to severe vertigo and nausea.
Step-by-step explanation:
The dysfunction in the semicircular canals of the vestibular system caused by a viral infection is called Vestibular neuritis. Vestibular neuritis is characterized by sudden and severe vertigo, often accompanied by nausea and vomiting. It is caused by inflammation of the vestibular nerve, which connects the semicircular canals to the brain.