What is the plural of virus?

Question: What is the plural of virus?

Answer: The plural of virus in English is viruses -- at least at the moment. Virus is a neuter noun in Latin, which means its plural, if there were an attested ancient usage of virus in the plural, would presumably have ended in an "a," because neuter nouns in ancient Greek and Latin ended in an "a," in the plural nominative and accusative cases. "Vira" is a possibility. "Viri" is the plural of the masculine noun "vir," which means man. Man is a masculine noun and the "i" ending is appropriate for the plural nominative of masculine second declension nouns. Although viruses is probably the best plural for virus, languages change and because of the frequency with which viruses threaten the Internet, and the resultant frequency of articles using various endings on the word virus, we may have a new standard plural for virus before we know it.